{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,10]],"date-time":"2026-08-10T14:03:51Z","timestamp":1786370631246,"version":"build-2736575974"},"reference-count":77,"publisher":"MDPI AG","issue":"4","license":[{"start":{"date-parts":[[2020,4,18]],"date-time":"2020-04-18T00:00:00Z","timestamp":1587168000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/100010665","name":"H2020 Marie Sk\u0142odowska-Curie Actions","doi-asserted-by":"publisher","award":["765860"],"award-info":[{"award-number":["765860"]}],"id":[{"id":"10.13039\/100010665","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Nanomaterials"],"abstract":"<jats:p>Cr(VI) has several industrial applications but it is one of the most dangerous pollutants because of its carcinogenicity and high toxicity. Thus, the removal of Cr(VI) by photocatalytic reduction was investigated. The catalyst applied, Ce\u2013ZrO2, was immobilized, through a sol\u2013gel process on a silicon carbide (SiC) support, to increase the efficiency and avoid using suspended nanoparticles. The influence of initial pH, humic acid (HA), and catalyst dosage was investigated for Cr(VI) containing solutions. Then, a real galvanizing industry effluent (Cr(VI) = 77 mg L-1mg.L\u22121, Zn = 1789 mg L\u22121) was treated. It was observed that Cr(VI) adsorption and photoreduction are greatly favored at low pH values. HA can decrease Cr(VI) adsorption but also acts as holes scavenger, reducing the electron\u2013hole recombination, favoring then the photoreduction. With the immobilized Ce\u2013ZrO2, more than 97% of Cr(VI) was removed from the diluted effluent. These results indicate the feasibility to treat Cr(VI) effluents even in the presence of other metals and natural organic matter. The developed material has great chemical and mechanical resistances and avoids the use of nanoparticles, dangerous for the environment and hard to recover. Moreover, solar light can be used to drive the process, which contributes to the development of more sustainable, cleaner, and cost-effective wastewater treatments.<\/jats:p>","DOI":"10.3390\/nano10040779","type":"journal-article","created":{"date-parts":[[2020,4,21]],"date-time":"2020-04-21T03:23:06Z","timestamp":1587439386000},"page":"779","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":43,"title":["Photocatalytic Reduction of Cr(VI) in the Presence of Humic Acid Using Immobilized Ce\u2013ZrO2 under Visible Light"],"prefix":"10.3390","volume":"10","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-9965-5039","authenticated-orcid":false,"given":"Fabr\u00edcio Eduardo","family":"Bortot Coelho","sequence":"first","affiliation":[{"name":"Department of Chemistry, University of Torino, Via P.Giuria 7, 10125 Torino, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4016-9073","authenticated-orcid":false,"given":"Victor M.","family":"Candelario","sequence":"additional","affiliation":[{"name":"LiqTech International A\/S, Industriparken 22 C, 2750 Ballerup, Denmark"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Est\u00eav\u00e3o Magno Rodrigues","family":"Ara\u00fajo","sequence":"additional","affiliation":[{"name":"Chemical Engineering Department, Federal University of Minas Gerais, Av.Ant\u00f4nio Carlos 6627, 30000-000 Belo Horizonte, Brazil"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"T\u00e2nia L\u00facia Santos","family":"Miranda","sequence":"additional","affiliation":[{"name":"Chemical Engineering Department, Federal University of Minas Gerais, Av.Ant\u00f4nio Carlos 6627, 30000-000 Belo Horizonte, Brazil"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3798-5232","authenticated-orcid":false,"given":"Giuliana","family":"Magnacca","sequence":"additional","affiliation":[{"name":"Department of Chemistry, University of Torino, Via P.Giuria 7, 10125 Torino, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2020,4,18]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1677","DOI":"10.1016\/j.chemosphere.2005.10.005","article-title":"Removal of Cr(VI) and humic acid by using TiO2 photocatalysis","volume":"63","author":"Yang","year":"2006","journal-title":"Chemosphere"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"267","DOI":"10.1016\/S0926-3373(98)00020-4","article-title":"Photocatalytic reduction of environmental pollutant Cr(VI) over some semiconductors under UV\/visible light illumination","volume":"17","author":"Khalil","year":"1998","journal-title":"Appl. Catal. B Environ."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"655","DOI":"10.1016\/j.jhazmat.2007.09.009","article-title":"Hexavalent chromium reduction with scrap iron in continuous-flow system","volume":"153","author":"Gheju","year":"2008","journal-title":"J. Hazard. Mater."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"68","DOI":"10.1016\/j.jece.2017.11.060","article-title":"Photocatalytic reduction of chromium (VI) using combustion synthesized TiO2","volume":"6","author":"Sane","year":"2018","journal-title":"J. Environ. Chem. Eng."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"396","DOI":"10.1016\/j.jhazmat.2008.06.104","article-title":"Biosorption of hexavalent chromium by raw and acid-treated green alga Oedogonium hatei from aqueous solutions","volume":"163","author":"Gupta","year":"2009","journal-title":"J. Hazard. Mater."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/S0041-008X(03)00011-5","article-title":"Potential hazards of hexavalent chromate in our drinking water","volume":"188","author":"Costa","year":"2003","journal-title":"Toxicol. Appl. Pharmacol."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"212","DOI":"10.1016\/j.jhazmat.2005.10.023","article-title":"Effects of tri-valent (Cr(III)) and hexa-valent (Cr(VI)) chromium on the growth of activated sludge","volume":"133","author":"Gikas","year":"2006","journal-title":"J. Hazard. Mater."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"894","DOI":"10.2166\/wpt.2017.094","article-title":"Phytoremediation of chromium from tannery wastewater using local plant species","volume":"12","author":"Kassaye","year":"2017","journal-title":"Water Pract. Technol."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"1973","DOI":"10.1149\/MA2018-01\/32\/1973","article-title":"Nanoporous MnO2 Nanoflakes Modified Carbon Cloth Material for Efficient Removal of Heavy Metal Ions in Water by Capacitive Deionization","volume":"MA2018-01","author":"Wang","year":"2018","journal-title":"Meet. Abstr."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"1567","DOI":"10.1016\/j.scitotenv.2017.12.195","article-title":"Removal of hexavalent chromium in aqueous solutions using biochar: Chemical and spectroscopic investigations","volume":"625","author":"Rajapaksha","year":"2018","journal-title":"Sci. Total Environ."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"1008","DOI":"10.1016\/j.jece.2018.01.026","article-title":"Nanostructured oxide stabilized by chitosan: Hybrid composite as an adsorbent for the removal of chromium (VI)","volume":"6","author":"Chagas","year":"2018","journal-title":"J. Environ. Chem. Eng."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"9","DOI":"10.1186\/s12199-018-0699-y","article-title":"Melanin-embedded materials effectively remove hexavalent chromium (CrVI) from aqueous solution","volume":"23","author":"Cuong","year":"2018","journal-title":"Environ. Health Prev. Med."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"187","DOI":"10.1016\/S0926-3373(97)00073-8","article-title":"Heterogeneous photocatalytic reactions of nitrite oxidation and Cr(VI) reduction on iron-doped titania prepared by the wet impregnation method","volume":"16","author":"Trillas","year":"1998","journal-title":"Appl. Catal. B Environ."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"341","DOI":"10.1016\/0300-483X(84)90050-7","article-title":"The reduction of chromium (VI) to chromium (III) by glutathione: An intracellular redox pathway in the metabolism of the carcinogen chromate","volume":"33","author":"Wiegand","year":"1984","journal-title":"Toxicology"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"873","DOI":"10.1002\/tcr.201800153","article-title":"Progress on the Photocatalytic Reduction Removal of Chromium Contamination","volume":"19","author":"Zhao","year":"2019","journal-title":"Chem. Rec."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"19","DOI":"10.4103\/2277-9183.157720","article-title":"Hexavalent chromium removal by titanium dioxide photocatalytic reduction and the effect of phenol and humic acid on its removal efficiency","volume":"4","author":"Malakootian","year":"2015","journal-title":"Int. J. Environ. Health Eng."},{"key":"ref_17","doi-asserted-by":"crossref","unstructured":"Yan, X., Ning, G., and Zhao, P. (2019). Enhanced Visible Light Photocatalytic Reduction of Cr(VI) over a Novel Square Nanotube Poly(Triazine Imide)\/TiO2 Heterojunction. Catalysts, 9.","DOI":"10.3390\/catal9010055"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1155\/2013\/582058","article-title":"Photocatalytic Degradation of Acid Yellow 36 Using Zinc Oxide Photocatalyst in Aqueous Media","volume":"2013","author":"Khezrianjoo","year":"2013","journal-title":"J. Catal."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"231","DOI":"10.1016\/S1010-6030(01)00423-3","article-title":"Photocatalytic degradation of 2-phenylphenol on TiO2 and ZnO in aqueous suspensions","volume":"141","author":"Khodja","year":"2001","journal-title":"J. Photochem. Photobiol. A Chem."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"299","DOI":"10.1016\/S0272-8842(00)00080-8","article-title":"Chemical stability of yttria doped zirconia membranes in acid and basic aqueous solutions: Chemical properties, effect of annealing and ageing time","volume":"27","author":"Shojai","year":"2001","journal-title":"Ceram. Int."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"311","DOI":"10.1016\/j.apcatb.2012.05.042","article-title":"Isomorphous substitution of Zr in the framework of aluminosilicate HY by an electrochemical method: Evaluation by methylene blue decolorization","volume":"125","author":"Sapawe","year":"2012","journal-title":"Appl. Catal. B Environ."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"447","DOI":"10.1021\/jz402731s","article-title":"Cerium-doped zirconium dioxide, a visible-light-sensitive photoactive material of third generation","volume":"5","author":"Gionco","year":"2014","journal-title":"J. Phys. Chem. Lett."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"100","DOI":"10.1016\/j.cattod.2018.01.030","article-title":"ZrO2 Based materials as photocatalysts for 2-propanol oxidation by using UV and solar light irradiation and tests for CO2 reduction","volume":"313","author":"Pomilla","year":"2018","journal-title":"Catal. Today"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"5906","DOI":"10.1166\/asl.2017.9065","article-title":"New Photoactive Materials Based on Zirconium Dioxide Doped with Rare Earth Metal Ions","volume":"23","author":"Paganini","year":"2017","journal-title":"Adv. Sci. Lett."},{"key":"ref_25","doi-asserted-by":"crossref","unstructured":"Bortot Coelho, F., Gionco, C., Paganini, M., Calza, P., and Magnacca, G. (2019). Control of Membrane Fouling in Organics Filtration Using Ce-Doped Zirconia and Visible Light. Nanomaterials, 9.","DOI":"10.3390\/nano9040534"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"368","DOI":"10.3389\/fchem.2018.00368","article-title":"Insights Into the Sunlight-Driven Water Oxidation by Ce and Er-Doped ZrO2","volume":"6","author":"Gionco","year":"2018","journal-title":"Front. Chem."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"012014","DOI":"10.1088\/1742-6596\/429\/1\/012014","article-title":"Interaction of fibrinogen and albumin with titanium dioxide nanoparticles of different crystalline phases","volume":"429","author":"Marucco","year":"2013","journal-title":"J. Phys. Conf. Ser."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"4614","DOI":"10.1002\/chem.200802542","article-title":"Non-UV-Induced Radical Reactions at the Surface of TiO2 Nanoparticles That May Trigger Toxic Responses","volume":"15","author":"Fenoglio","year":"2009","journal-title":"Chem. A Eur. J."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"159","DOI":"10.1016\/j.jcis.2005.08.007","article-title":"Kinetics of heterogeneous photocatalytic degradation of reactive dyes in an immobilized TiO2 photocatalytic reactor","volume":"295","author":"Mahmoodi","year":"2006","journal-title":"J. Colloid Interface Sci."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/j.apcatb.2005.02.013","article-title":"UV-induced photocatalytic degradation of azo dyes by organic-capped ZnO nanocrystals immobilized onto substrates","volume":"60","author":"Comparelli","year":"2005","journal-title":"Appl. Catal. B Environ."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"53","DOI":"10.1016\/j.apcatb.2006.12.015","article-title":"Immobilization of TiO2 on perlite granules for photocatalytic degradation of phenol","volume":"74","author":"Hosseini","year":"2007","journal-title":"Appl. Catal. B Environ."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"207","DOI":"10.1080\/02772249709358508","article-title":"Speciation analysis of chromium after reduction of chromium (VI) by humic acid","volume":"62","author":"Fukushima","year":"1997","journal-title":"Toxicol. Environ. Chem."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"740","DOI":"10.1016\/j.envpol.2017.10.120","article-title":"The role of different functional groups in a novel adsorption-complexation-reduction multi-step kinetic model for hexavalent chromium retention by undissolved humic acid","volume":"237","author":"Zhang","year":"2018","journal-title":"Environ. Pollut."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"580","DOI":"10.1021\/es9803207","article-title":"Effect of Solution Chemistry on the Extent of Binding of Phenanthrene by a Soil Humic Acid: A Comparison of Dissolved and Clay Bound Humic","volume":"33","author":"Jones","year":"1999","journal-title":"Environ. Sci. Technol."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"4804","DOI":"10.1021\/es0200084","article-title":"Complexation with Dissolved Organic Matter and Solubility Control of Heavy Metals in a Sandy Soil","volume":"36","author":"Weng","year":"2002","journal-title":"Environ. Sci. Technol."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"6308","DOI":"10.1021\/acs.est.7b00371","article-title":"Effect of Humic Acid on the Removal of Chromium(VI) and the Production of Solids in Iron Electrocoagulation","volume":"51","author":"Pan","year":"2017","journal-title":"Environ. Sci. Technol."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"139","DOI":"10.1016\/j.matlet.2014.05.093","article-title":"Solvothermal synthesis of visible-light-active N-modified ZrO2 nanoparticles","volume":"130","author":"Zhao","year":"2014","journal-title":"Mater. Lett."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"371","DOI":"10.1016\/j.surfcoat.2016.12.026","article-title":"Synthesis of freestanding amorphous ZrO2 nanotubes by anodization and their application in photoreduction of Cr(VI) under visible light","volume":"320","author":"Bashirom","year":"2017","journal-title":"Surf. Coat. Technol."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"1122","DOI":"10.1016\/j.cej.2016.11.080","article-title":"Fabrication of mesoporous CuO\/ZrO2 -MCM-41 nanocomposites for photocatalytic reduction of Cr(VI)","volume":"316","author":"Nanda","year":"2017","journal-title":"Chem. Eng. J."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"185","DOI":"10.1016\/S0926-860X(02)00051-0","article-title":"Effect of ZrO2 incorporation and calcination temperature on the photocatalytic activity of commercial TiO2 for salicylic acid and Cr(VI) photodegradation","volume":"231","author":"Hidalgo","year":"2002","journal-title":"Appl. Catal. A Gen."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"112105","DOI":"10.1016\/j.jphotochem.2019.112105","article-title":"Structural and photochemical properties of Fe-doped ZrO2 and their application as photocatalysts with TiO2 for chromate reduction","volume":"386","author":"Doufar","year":"2020","journal-title":"J. Photochem. Photobiol. A Chem."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"245","DOI":"10.1016\/j.cattod.2007.07.010","article-title":"EXAFS study and photocatalytic properties of un-doped and iron-doped ZrO2-TiO2 (photo-) catalysts","volume":"128","author":"Hidalgo","year":"2007","journal-title":"Catal. Today"},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"89","DOI":"10.1016\/S1010-6030(99)00150-1","article-title":"Photocatalytic properties of ZrO2 and Fe\/ZrO2 semiconductors prepared by a sol\u2013gel technique","volume":"129","author":"Botta","year":"1999","journal-title":"J. Photochem. Photobiol. A Chem."},{"key":"ref_44","doi-asserted-by":"crossref","unstructured":"Neufert, R., Moeller, M., and Bakshi, A.K. (2013). Dead-End Silicon Carbide Micro-Filters for Liquid Filtration. Advances in Bioceramics and Porous Ceramics VI, Wiley-American Ceramic Society.","DOI":"10.1002\/9781118807811.ch10"},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"4957","DOI":"10.1016\/j.ces.2004.07.015","article-title":"Preparation and reactive applications of nanoporous silicon carbide membranes","volume":"59","author":"Ciora","year":"2004","journal-title":"Chem. Eng. Sci."},{"key":"ref_46","doi-asserted-by":"crossref","unstructured":"Fraga, M., Sanches, S., Crespo, J., and Pereira, V. (2017). Assessment of a New Silicon Carbide Tubular Honeycomb Membrane for Treatment of Olive Mill Wastewaters. Membranes, 7.","DOI":"10.3390\/membranes7010012"},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"159","DOI":"10.1016\/0376-7388(96)00086-5","article-title":"Preparation of thermostable amorphous Si-C-O membrane and its application to gas separation at elevated temperature","volume":"118","author":"Zhongyang","year":"1996","journal-title":"J. Memb. Sci."},{"key":"ref_48","doi-asserted-by":"crossref","unstructured":"Eray, E., Boffa, V., J\u00f8rgensen, M.K., Magnacca, G., and Candelario, V.M. (2020). Enhanced Fabrication of Silicon Carbide Membranes for Wastewater Treatment: From Laboratory to Industrial Scale. J. Memb. Sci., 118080.","DOI":"10.1016\/j.memsci.2020.118080"},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"399","DOI":"10.1016\/j.seppur.2019.03.066","article-title":"Hydrothermally stable mesoporous ZrO2 membranes prepared by a facile nanoparticle deposition process","volume":"221","author":"Gestel","year":"2019","journal-title":"Sep. Purif. Technol."},{"key":"ref_50","unstructured":"Rice, E.W., Baird, R.B., Eaton, A.D., and Clesceri, L.S. (2012). Standard Methods for the Examination of Water and Wastewater, American Public Health Association."},{"key":"ref_51","doi-asserted-by":"crossref","first-page":"633","DOI":"10.1016\/j.cej.2016.05.095","article-title":"Novel titanium dioxide\/iron (III) oxide\/graphene oxide photocatalytic membrane for enhanced humic acid removal from water","volume":"302","author":"Rao","year":"2016","journal-title":"Chem. Eng. J."},{"key":"ref_52","doi-asserted-by":"crossref","first-page":"16","DOI":"10.1016\/j.jhazmat.2013.08.037","article-title":"Adsorption-photodegradation of humic acid in water by using ZnO coupled TiO2\/bamboo charcoal under visible light irradiation","volume":"262","author":"Wang","year":"2013","journal-title":"J. Hazard. Mater."},{"key":"ref_53","doi-asserted-by":"crossref","first-page":"374","DOI":"10.1016\/j.molliq.2015.07.052","article-title":"Removal of humic acid from aqueous solution using UV\/ZnO nano-photocatalysis and adsorption","volume":"213","author":"Oskoei","year":"2016","journal-title":"J. Mol. Liq."},{"key":"ref_54","doi-asserted-by":"crossref","first-page":"3882","DOI":"10.1016\/S0043-1354(00)00120-2","article-title":"Destruction of humic acid in water by UV light catalyzed oxidation with hydrogen peroxide","volume":"34","author":"Wang","year":"2000","journal-title":"Water Res."},{"key":"ref_55","doi-asserted-by":"crossref","first-page":"78","DOI":"10.1016\/j.cattod.2016.06.020","article-title":"Application of Fe-doped TiO2specimens for the solar photocatalytic degradation of humic acid","volume":"281","author":"Birben","year":"2017","journal-title":"Catal. Today"},{"key":"ref_56","doi-asserted-by":"crossref","first-page":"270","DOI":"10.1016\/j.jechem.2016.07.006","article-title":"Rare earth oxides in zirconium dioxide: How to turn a wide band gap metal oxide into a visible light active photocatalyst","volume":"26","author":"Gionco","year":"2017","journal-title":"J. Energy Chem."},{"key":"ref_57","doi-asserted-by":"crossref","first-page":"317","DOI":"10.1016\/j.jiec.2014.07.025","article-title":"Photocatalytic reduction of hexavalent chromium with illuminated ZnO\/TiO2 composite","volume":"22","author":"Yang","year":"2015","journal-title":"J. Ind. Eng. Chem."},{"key":"ref_58","doi-asserted-by":"crossref","first-page":"135","DOI":"10.1016\/S0043-1354(00)00098-1","article-title":"Photocatalytic reduction of Cr(VI) in aqueous solutions by UV irradiation with the presence of titanium dioxide","volume":"35","author":"Ku","year":"2001","journal-title":"Water Res."},{"key":"ref_59","doi-asserted-by":"crossref","first-page":"598","DOI":"10.1021\/es950368+","article-title":"Humic acid-sensitized photoreduction of Cr(VI) on ZnO particles","volume":"30","author":"Selli","year":"1996","journal-title":"Environ. Sci. Technol."},{"key":"ref_60","doi-asserted-by":"crossref","first-page":"11302","DOI":"10.1021\/acs.chemrev.7b00161","article-title":"Generation and Detection of Reactive Oxygen Species in Photocatalysis","volume":"117","author":"Nosaka","year":"2017","journal-title":"Chem. Rev."},{"key":"ref_61","doi-asserted-by":"crossref","first-page":"349","DOI":"10.1007\/BF02708383","article-title":"Characterization of combustion synthesized zirconia powder by UV-vis, IR and other techniques","volume":"23","year":"2000","journal-title":"Bull. Mater. Sci."},{"key":"ref_62","doi-asserted-by":"crossref","first-page":"765","DOI":"10.1016\/j.jhazmat.2010.11.063","article-title":"Synergy between surface adsorption and photocatalysis during degradation of humic acid on TiO2\/activated carbon composites","volume":"186","author":"Xue","year":"2011","journal-title":"J. Hazard. Mater."},{"key":"ref_63","doi-asserted-by":"crossref","unstructured":"Suchanek, M., Niewiara, E., Wilkosz, K., and Kubiak, W.W. (2019). Nanopowders of Yttria-Stabilized Zirconia Doped with Rare Earth Elements as Adsorbents of Humic Acids. Materials, 12.","DOI":"10.3390\/ma12233915"},{"key":"ref_64","doi-asserted-by":"crossref","first-page":"409","DOI":"10.2343\/geochemj.2.0222","article-title":"Speciation study of Cr(VI\/III) reacting with humic substances and determination of local structure of Cr binding humic substances using XAFS spectroscopy","volume":"46","author":"Ohta","year":"2013","journal-title":"Geochem. J."},{"key":"ref_65","doi-asserted-by":"crossref","first-page":"375701","DOI":"10.1088\/1361-6528\/aaccbd","article-title":"Sunlight activated anodic freestanding ZrO2 nanotube arrays for Cr(VI) photoreduction","volume":"29","author":"Bashirom","year":"2018","journal-title":"Nanotechnology"},{"key":"ref_66","doi-asserted-by":"crossref","unstructured":"Haynes, W.M. (2014). CRC Handbook of Chemistry and Physics, CRC Press.","DOI":"10.1201\/b17118"},{"key":"ref_67","doi-asserted-by":"crossref","first-page":"27","DOI":"10.1021\/ja00339a007","article-title":"Electrochemical investigation of the energetics of particulate titanium dioxide photocatalysts. The methyl viologen-acetate system","volume":"105","author":"Ward","year":"1983","journal-title":"J. Am. Chem. Soc."},{"key":"ref_68","doi-asserted-by":"crossref","first-page":"2219","DOI":"10.1081\/ESE-120023356","article-title":"Treatment of Cr(VI) and Phenol by Illuminated TiO2","volume":"38","author":"Lee","year":"2003","journal-title":"J. Environ. Sci. Heal. Part A"},{"key":"ref_69","doi-asserted-by":"crossref","first-page":"55","DOI":"10.2166\/wst.2014.193","article-title":"Reduction of hexavalent chromium: Photocatalysis and photochemistry and their application in wastewater remediation","volume":"70","author":"Machado","year":"2014","journal-title":"Water Sci. Technol."},{"key":"ref_70","doi-asserted-by":"crossref","first-page":"14483","DOI":"10.1016\/j.ijhydene.2015.05.180","article-title":"Evaluation of the anatase\/rutile phase composition influence on the photocatalytic performances of mesoporous TiO2 powders","volume":"40","author":"Masolo","year":"2015","journal-title":"Int. J. Hydrog. Energy"},{"key":"ref_71","doi-asserted-by":"crossref","first-page":"2243","DOI":"10.1021\/cm400728j","article-title":"Paramagnetic Defects in Polycrystalline Zirconia: An EPR and DFT Study","volume":"25","author":"Gionco","year":"2013","journal-title":"Chem. Mater."},{"key":"ref_72","doi-asserted-by":"crossref","first-page":"518","DOI":"10.1007\/BF01076066","article-title":"TiO2 catalysed reduction of Cr(VI) in aqueous solutions under ultraviolet illumination","volume":"20","author":"Munoz","year":"1990","journal-title":"J. Appl. Electrochem."},{"key":"ref_73","doi-asserted-by":"crossref","first-page":"269","DOI":"10.1016\/j.jhazmat.2004.05.013","article-title":"Photocatalytic degradation of model textile dyes in wastewater using ZnO as semiconductor catalyst","volume":"112","author":"Chakrabarti","year":"2004","journal-title":"J. Hazard. Mater."},{"key":"ref_74","doi-asserted-by":"crossref","first-page":"132","DOI":"10.1016\/j.apcatb.2015.09.015","article-title":"Degradation of pharmaceuticals in wastewater using immobilized TiO2 photocatalysis under simulated solar irradiation","volume":"182","author":"He","year":"2016","journal-title":"Appl. Catal. B Environ."},{"key":"ref_75","doi-asserted-by":"crossref","first-page":"274","DOI":"10.1016\/j.apcatb.2014.02.035","article-title":"WO3\u2013TiO2 based catalysts for the simulated solar radiation assisted photocatalytic ozonation of emerging contaminants in a municipal wastewater treatment plant effluent","volume":"154\u2013155","author":"Rey","year":"2014","journal-title":"Appl. Catal. B Environ."},{"key":"ref_76","doi-asserted-by":"crossref","first-page":"191","DOI":"10.1016\/j.jhazmat.2006.08.004","article-title":"Adsorption of Cr(VI) from synthetic solutions and electroplating wastewaters on amorphous aluminium oxide","volume":"142","author":"Querol","year":"2007","journal-title":"J. Hazard. Mater."},{"key":"ref_77","doi-asserted-by":"crossref","unstructured":"Wu, B., Zhang, L., Wei, S., Ou\u2019Yang, L., Yin, R., and Zhang, S. (2019). Reduction of chromate with UV\/diacetyl for the final effluent to be below the discharge limit. J. Hazard. Mater.","DOI":"10.1016\/j.jhazmat.2019.121841"}],"container-title":["Nanomaterials"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2079-4991\/10\/4\/779\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,13]],"date-time":"2025-10-13T13:45:06Z","timestamp":1760363106000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2079-4991\/10\/4\/779"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2020,4,18]]},"references-count":77,"journal-issue":{"issue":"4","published-online":{"date-parts":[[2020,4]]}},"alternative-id":["nano10040779"],"URL":"https:\/\/doi.org\/10.3390\/nano10040779","relation":{},"ISSN":["2079-4991"],"issn-type":[{"value":"2079-4991","type":"electronic"}],"subject":[],"published":{"date-parts":[[2020,4,18]]}}}