Visible-light-driven CO2 reduction with g-C3N4-based composite: Enhancing the activity of manganese catalysts

A heterogeneous photocatalytic system that consists of a manganese complex and g-C3N4, which mainly act as the catalytic and light-harvesting units, respectively, was developed for the reduction of CO2 to CO. The anchoring group (carboxyl) and the structure of g-C3N4 promote electron transfer from g-C3N4 to the manganese unit and strengthen electronic interactions between the two units. The photocatalytic prop-erties and stability of a tricarbonyl Mn bipyridyl complex were significantly enhanced by anchoring on a g-C3N4 support. The turnover number for CO formation reached 75.7 under the optimal reaction conditions. This photocatalytic system is environmentally friendly and sustainable, and will stimulate the development of potential photocatalytic CO2 transformation methods that use solar energy. (C) 2020 Elsevier Ltd. All rights reserved.