{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,23]],"date-time":"2026-09-23T05:02:59Z","timestamp":1790139779408,"version":"4.0.1"},"reference-count":57,"publisher":"MDPI AG","issue":"18","license":[{"start":{"date-parts":[[2026,9,14]],"date-time":"2026-09-14T00:00:00Z","timestamp":1789344000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Shandong Province Natural Science","award":["ZR2019MB021"],"award-info":[{"award-number":["ZR2019MB021"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Molecules"],"abstract":"<jats:p>Lead-free palladium halides containing square-planar coordination units provide a distinctive platform for investigating light-matter interactions, yet their spectroscopic behavior and thin-film photoresponse remain largely unexplored. Herein, we report a systematic investigation of Cs2PdCl4\u00b7H2O, synthesized as both nanorods and single crystals, covering its structural, spectroscopic, electronic, and photoresponsive properties. Single-crystal X-ray diffraction confirms that the monohydrate crystallizes in the orthorhombic Cmcm space group with discrete square-planar [PdCl4]2\u2212 units. Powder X-ray diffraction verifies that the nanorods adopt the same crystalline phase and retain their principal diffraction features after two months of ambient storage. X-ray photoelectron spectroscopy confirms the Pd(II) valence state, and optical measurements determine a direct bandgap of 2.32 eV. Temperature-dependent and time-resolved photoluminescence reveal a low-temperature emission blueshift, enhanced emission intensity, and prolonged carrier decay, attributable to suppressed non-radiative relaxation and contributions from multiple emissive states. Density functional theory calculations based on the experimentally determined monohydrate structure show that the band-edge states are dominated by Cl 3p and Pd 4d orbitals. Thermally deposited Cs2PdCl4\u00b7H2O-derived films deliver reproducible visible-light photocurrent switching across 397\u2013564 nm and retain 71% of their initial response after 504 h under nitrogen. These findings establish Cs2PdCl4\u00b7H2O as a visible-light-responsive lead-free palladium halide and provide a basis for future exploration in optoelectronic sensing.<\/jats:p>","DOI":"10.3390\/molecules31183259","type":"journal-article","created":{"date-parts":[[2026,9,14]],"date-time":"2026-09-14T15:19:04Z","timestamp":1789399144000},"page":"3259","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Synthesis, Crystal Structure, Spectroscopic Properties, and Visible-Light Photoresponse of Lead-Free Cs2PdCl4\u00b7H2O"],"prefix":"10.3390","volume":"31","author":[{"ORCID":"https:\/\/orcid.org\/0009-0006-1530-4025","authenticated-orcid":false,"given":"Wenhuan","family":"Cao","sequence":"first","affiliation":[{"name":"School of Materials Science and Engineering, Liaocheng University, Liaocheng 252000, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Chen","family":"Wang","sequence":"additional","affiliation":[{"name":"School of Chemistry and Chemical Engineering, Liaocheng University, Liaocheng 252000, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yu","family":"Li","sequence":"additional","affiliation":[{"name":"School of Chemistry and Chemical Engineering, Liaocheng University, Liaocheng 252000, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0004-3009-1043","authenticated-orcid":false,"given":"Jie","family":"Yin","sequence":"additional","affiliation":[{"name":"School of Materials Science and Engineering, Liaocheng University, Liaocheng 252000, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Huawei","family":"Zhou","sequence":"additional","affiliation":[{"name":"School of Chemistry and Chemical Engineering, Liaocheng University, Liaocheng 252000, China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,9,14]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/j.physrep.2024.06.001","article-title":"Integration of two-dimensional materials based photodetectors for on-chip applications","volume":"1081","author":"Wang","year":"2024","journal-title":"Phys. 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