Roy Anand, Singh Anjali, Aravindh S Assa, Servottam Swaraj, Waghmare Umesh V, Rao C N R
New Chemistry Unit, Sheikh Saqr Laboratory, School of Advanced Materials and Theoritical Science Unit, Jawharlal Nehru Centre for Advanced Scientific Research, Jakkur, P.O., 560064, Bangalore, India.
Angew Chem Int Ed Engl. 2019 May 20;58(21):6926-6931. doi: 10.1002/anie.201900936. Epub 2019 Apr 10.
We have carried out a combined experimental and theoretical investigation of the structures and properties of a family of cadmium phosphochlorides with varying Cl/Cd and P/Cd ratios, Cd P Cl, Cd P Cl , Cd PCl and Cd P Cl . Their optical band gaps are in the visible region and the values are sensitive to the Cl/Cd and P/Cd ratios, leading to an increase and decrease, respectively. First-principles calculations were used to understand the bonding and electronic structures. All phosphochlorides except Cd P Cl possess direct band gaps. The calculated dielectric constants and Born effective charges illustrate the bonding, hybridization, and ionic character in these compounds. The band positions indicate the thermodynamic feasibility to perform water splitting. All systems can be used in the hydrogen evolution reaction (HER), where Cd P Cl has the highest activity and Cd PCl the lowest. The apparent quantum yield is highest in Cd P Cl (20.1 %) even without the assistance of a co-catalyst. The HER activity can be understood on the basis of photoelectrochemical measurements.
我们对一系列具有不同Cl/Cd和P/Cd比率的磷氯化镉（CdPCl、Cd₂PCl、CdPCl₂和Cd₂PCl₃）的结构和性质进行了实验与理论相结合的研究。它们的光学带隙处于可见光区域，且其值对Cl/Cd和P/Cd比率敏感，分别导致带隙增大和减小。采用第一性原理计算来理解其键合和电子结构。除Cd₂PCl₃外，所有磷氯化物都具有直接带隙。计算得到的介电常数和玻恩有效电荷说明了这些化合物中的键合、杂化和离子特性。能带位置表明了进行水分解的热力学可行性。所有体系都可用于析氢反应（HER），其中CdPCl的活性最高，CdPCl₂的活性最低。即使在没有助催化剂的情况下，Cd₂PCl₃的表观量子产率也是最高的（20.1%）。基于光电化学测量可以理解HER活性。
