The development of green and efficient photocatalytic materials for the treatment of medical and industrial wastewater has become a current research focus. In this work, the CeO 2 /Zn 0.4 Cd 0.6 S heterojunction with a special 0D/1D morphology was synthesized by a soft chemistry method. The successful construction of the heterojunction was verified by the binding energy migration of XPS and TEM . The photocatalytic activities were determined by photoreduction of hexavalent chromium ions (Cr VI ) and photodegradation of tetracycline hydrochloride (TC). The experimental results showed that the loading of CeO 2 significantly improves the photocatalytic performance of Zn 0.4 Cd 0.6 S, and the loading of 10 wt% CeO 2 has the best photocatalytic activity and structural stability. The S-scheme electron transport mechanism was particularly investigated through active species trapping experiments. This work provides an effective idea for the design of highly stable metal sulfide photocatalysts .
Yanze Wang,Zhenyu Liu,Wenxuan Wang,Junxiao Tang,Rongjie Wang,Jingjing Xie,Zhengyi Fu
Accelerating charge transport and avoiding recombination are promising strategies for establishing highly efficient artificial photosystems. Herein, an S-scheme heterostructure consisting of Zn x Cd 1− x S and TiO 2 is fabricated via the in situ crystal growth method. The refined structure significantly enhances the transport of photogenerated charges, thereby improving photocatalytic hydrogen production efficiency. The optimized TiO 2 −Zn x Cd 1− x S composite, incorporating 60% TiO 2 with Zn 0.4 Cd 0.6 S, exhibits a robust H 2 evolution rate of 50.96 mmol g −1 h −1 with continuous release of H 2 bubbles. It is worth noting that the hydrogen production rate in seawater is as high as 26.22 mmol g −1 h −1 . The strong interfacial interaction and staggered band alignment between TiO 2 and Zn x Cd 1− x S result in the formation of a built-in electric field and high-content oxygen vacancies, which can drive the directional migration of photoelectrons with high redox ability and high speed. The designed photocatalyst with S-scheme and rich Oxygen vacancies at the interface provides a new approach for fabricating high-efficiency photocatalysts.
To enhance the hydrogen production performance and photo-corrosion resistance of ZnS and CdS based photocatalysts without relying on noble metals such as platinum, ruthenium, or gold, this study optimizes the molar ratio between Cd and Zn in Zn x Cd 1-x S solid solutions. The resulting Zn 0.4 Cd 0.6 S nanorod-shaped solid solutions exhibit superior visible-light photocatalytic activity. A non-precious metal Ni 3 (PO 4 ) 2 nano-thin layer is uniformly deposited onto the surface of the Zn 0.4 Cd 0.6 S solid solution via a room-temperature chemical co-precipitation method. This modification not only prevents oxidative photo-corrosion but also facilitates the oxidation and reduction of water during the photocatalytic surface process, significantly enhancing both the stability and hydrogen production performance of the composite catalyst. Experimental results demonstrate that the performance improvement of Zn 0.4 Cd 0.6 S by the Ni 3 (PO 4 ) 2 cocatalyst is markedly greater than that achieved with the traditional Pt cocatalyst. The maximum hydrogen production rate of the composite catalyst reaches 119.72 mmol·g⁻¹·h⁻¹, with an accumulated hydrogen production of 340.33 mmol·g⁻¹ after 3 hours. After 25 hours of photocatalytic cycling experiments, the hydrogen production rate remains at 95.95 mmol·g⁻¹·h⁻¹, approximately 80.14 % of the initial rate. The apparent quantum yield of Z4C6S-5NPO attains 61.8 %, with high value in ZnCdS-based photocatalysts. These results are promising and offer valuable insights for the development of low-cost, highly stable, and efficient composite photocatalysts.