Boosted interfacial charge transfer on CoO/Zn _0.5 Cd _0.5 S for simultaneous photocatalytic H ₂ production and sewage purification

Abstract Harnessing solar energy for simultaneous hydrogen evolution and sewage purification with organic contaminants via photocatalysis represents an effective strategy for sustainable energy conversion and environmental protection. In this work, an innovative 2D/0D CoO/Zn 0.5 Cd 0.5 S heterointerface catalyst was fabricated using a straightforward hybridization technique. The catalyst was used for photocatalytic hydrogen evolution in solutions with inorganic sacrificial agents (S 2 /SO 3 2– ), ultrapure water, and Rhodamine B (RhB) dye. Remarkably, the optimized 2D/0D 5% CoO/Zn 0.5 Cd 0.5 S catalyst demonstrated an exceptional hydrogen evolution rate of 2688 μmol g −1 h −1 under visible‐light irradiation, approximately 25‐fold higher than that of pure Zn 0.5 Cd 0.5 S. Furthermore, it efficiently generates hydrogen while concurrently purifying RhB. The ultrathin CoO nanosheets uniformly disperse Zn 0.5 Cd 0.5 S nanoparticles, providing numerous catalytic active sites. In situ X‐ray photoelectron spectroscopy analysis elucidates photogenerated electron transfer from layered CoO to Zn and Cd in Zn 0.5 Cd 0.5 S during photocatalysis. Photoluminescent spectra, femtosecond transient absorption (fs‐TA) spectroscopy, photoelectrochemical measurements, ultraviolet photoelectron spectroscopy and first‐principles calculations further confirm that the intrinsic electric field at the CoO/Zn 0.5 Cd 0.5 S heterointerface enhances photogenerated electron–hole separation and mobility. The outcomes of this research offer valuable insights into developing economical photocatalysts for efficient hydrogen production and concurrent sewage purification with organic pollutants.