Coordination Polymer MC₂O₄ (M = Ni, Co) for Enhanced Photocatalytic Hydrogen Evolution

基于半导体的光催化水分解生产绿色氢气技术被认为是解决能源问题的理想出路。形成复合异质结材料可以有效地提高光催化材料产氢效率和稳定性。本文采用湿化学法分别合成CoC2O4与NiC2O4并对Mn0.5Cd0.5S进行复合改性与修饰，并采用SEM、XRD、Mott-Schottky、DRS和EIS等技术对其进行了表征。结果表明，CoC2O4和NiC2O4的加入可以通过不同的方式提升光催化复合材料的光催化产氢性能。CoC2O4与Mn0.5Cd0.5S形成II型异质结结构，在内电场的作用下，对电子进行转移。而NiC2O4则作为助催化剂，对电子产生聚集，两者均达到了光生载流子的空间分离效果，降低空穴和电子的复合几率，更进一步地表明出CoC2O4与NiC2O4的加入可以提高光催化产氢的效率和稳定性。这项工作为可持续能源应用的高性能异质结光催化剂的合理设计提供了有价值的参考。The semiconductor-based photocatalytic water splitting technology for green hydrogen production is regarded as an ideal solution to address energy challenges. Constructing composite heterojunction materials has proven effective in enhancing the photocatalytic hydrogen evolution efficiency and stability. In this study, CoC₂O₄ and NiC₂O₄ were synthesized via a wet chemical method to modify Mn0.5Cd0.5S through composite formation and surface decoration. The as-prepared materials were systematically characterized using SEM, XRD, Mott-Schottky analysis, DRS, and EIS techniques. Results demonstrate that the incorporation of CoC₂O₄ and NiC₂O₄ enhances the photocatalytic hydrogen production performance through distinct mechanisms. CoC₂O₄ forms a Type II heterojunction with Mn0.5Cd0.5S, facilitating electron transfer driven by the built-in electric field. In contrast, NiC₂O₄ acts as a co-catalyst to accumulate electrons. Both strategies achieve spatial separation of photogenerated charge carriers, effectively reducing the recombination probability of holes and electrons. Furthermore, the introduction of CoC₂O₄ and NiC₂O₄ significantly improves the photocatalytic hydrogen production efficiency and stability. This work provides mechanistic insights into the rational design of high-performance heterojunction photocatalysts for sustainable energy applications.