Ni掺杂提升MoS_(2)的助催化活性用于ZnIn_(2)S_(4)光催化产氢及有毒Cr(Ⅵ)还原

Ni doping to improve the cocatalytic activity of MoS_(2)cocatalyst for ZnIn_(2)S_(4)photocatalytic H_(2)production and toxic Cr(Ⅵ)reduction

过渡金属硫化物MoS_(2)吸附H^(+)的吉布斯自由能接近于零,被认为是一种很有前途的产氢助催化剂。然而,MoS_(2)助催化剂的活性位点暴露有限,极大的限制了其活性。以Ni-BDC微球作为Ni源和模板,通过水热法成功合成了镍掺杂的Ni-MoS_(2)助催化剂。该助催化剂可以明显的提高ZnIn_(2)S_(4)的光催化析氢活性活性,经过优化后的光催化剂(表示为NMS/ZIS-10)的氢气释放速率最高,达到4.17 mmol·g^(-1)·h^(-1),分别是纯ZnIn_(2)S_(4)和MoS_(2)/ZnIn_(2)S_(4)光催化剂的12.26倍和2.72倍。此外,NMS/ZIS-10还表现出电荷分离促进的毒性Cr(Ⅵ)还原活性。实验数据表明,Ni-MoS_(2)/ZnIn_(2)S_(4)优异的光催化性能主要源于其Ni掺杂引起的活性位点的增加、光吸收能力的增强、电荷载流子分离的提升以及电子寿命的延长。研究结果为优化设计高性能Mo基助催化剂提供了有价值的参考。

The Gibbs free energy of H^(+)adsorption on transition metal sulfide MoS_(2)is close to zero,considered to be a promising cocatalyst for hydrogen production.However,the limited exposure of the active sites of MoS_(2)cocatalyst limits the activity.In this work,Ni-BDC microspheres was chosen as Ni sources and templates to synthesize nickel doped MoS_(2)cocatalyst via a hydrothermal method.The cocatalyst can significantly improve the photocatalytic hydrogen evolution activity of ZnIn_(2)S_(4).The optimized photocatalyst(labelled as NMS/ZIS-10)exhibits the highest hydrogen evolution rate of 4.17 mmol/(g·h),which is 12.26 times and 2.72 times of pure ZnIn_(2)S_(4)and MoS_(2)/ZnIn_(2)S_(4)photocatalysts,respectively.In addition,NMS/ZIS-10 also exhibits significantly enhanced toxic Cr(Ⅵ)reduction activity due to the promoted charge separation.The excellent photocatalytic performance of Ni-MoS_(2)/ZnIn_(2)S_(4)is mainly due to the increase of active sites caused by Ni doping,the enhancement of light absorption ability,the improvement of charge carrier separation,and the extension of electronic lifetime.The results of this study provide valuable references for optimizing the design of high-performance Mo based co catalysts.