Heterojunction Engineering of Functional Catalysts for Photoelectrochemical CO2 Reduction

Abstract

In recent years, photoelectrochemically (PEC) CO2 reduction reaction (CO2RR) has emerged as one of the most promising methods to address global warming and the energy crisis by converting CO2 into valuable chemicals utilizing solar energy. Halide perovskite (PVK) materials, which have been broadly used for developing high-performance photovoltaics, have also shown immense potential for photocatalytic CO2 reduction, due to their excellent optoelectronic properties as well as their cost-effective raw materials and facile fabrication processing. However, the rational approach to directly applying this class of materials to photoelectrochemical (PEC) CO2 reduction remains unclear, in particular, given that this class of materials normally suffers from instability issues in the aqueous solution. Among metal-based catalysts, copper-tin (CuSn) composites have been widely reported for electrochemically reducing CO2RR to produce formic acid but have rarely been studied for PEC CO2RR.

In this thesis, with the aim of addressing the above-mentioned challenges, exploring more promising candidate materials in the field of PEC CO2RR, and gaining an in-depth understanding of the working mechanisms of these materials for PEC CO2RR, I carried out systematic research on using halide perovskite materials and CuSn composites as the active mediums for PEC CO2RR. In detail, I developed the facile solution-processed methods to grow the high-quality heterostructures and composts coupling the above-mentioned material systems with other functional materials and investigated the effect of interfaces on the material properties and the performance and stability of the related devices for PEC CO2RR.