Sulphur vacancy-rich PCdS/NiCoLDH promotes highly selective and efficient photocatalytic CO2 reduction to MeOH
Chandra Shobha Vennapoosa, Vijaya Tejavath, Yendrapati Taraka Prabhu, Amritanjali Tiwari, B. Moses Abraham, Vijaya Sarathi Upadhyayula, Ujjwal Pal
Abstract
In this report, a facile hydrothermal approach is employed in modulated phosphorus-doped CdS (PCdS) nanorods over optimal molar ratio of Ni & Co in LDH to engineer a robust hierarchical PCdS/NiCoLDH photocatalytic system for efficient reduction of CO 2 to methanol under visible light . The S vacancies and their impurity levels are approximately near towards the Fermi levels after interstitial P doping, and is found to be an efficient level to trap electrons in PCdS, which can affect the dynamic characteristics of photogenerated electrons and hence extend their lives. The time-dependent kinetics indicated the selective formation of CH 3 OH with 684 μmolg −1 cat, for 4 h (AQY= 3.8%) and 220 μmol - g −1 cat, (AQY= 1.3%) under 20 W LED lamp . The correlation between the electronic structures and photo physical properties of the defect rich photocatalyst is substantiated from the experimental and theoretical studies. The enhanced activity is attributed to the increased CO 2 absorption capacity over the mesoporous structures as well as the interlayer spaces. The sulphur vacancies over the PCdS can provide excess active sites towards activation, light absorption , as well as the CO 2 conversion. This work presents deep insights into the synthesis of NiCo-LDH-based materials with rationally designed carrier transfer behaviors for not only in photocatalytic reactions but also in photovoltaic fields.