Halogen-Modulated 2D Coordination Polymers for Efficient Hydrogen Peroxide Photosynthesis under Air and Pure Water Conditions

H2O2 is a widely used eco-friendly oxidant and a potential energy carrier. Photocatalytic H2O2 production from water and O2 is an ideal approach with the potential to address the current energy crisis and environmental issues. Three zig-zag two-dimensional coordination polymers (2D CPs), named CuX-dptz, were synthesized by a rapid and facile method at room temperature, showing preeminent H2O2 photoproduction performance under pure water and open air without any additives. CuBr-dptz exhibits a H2O2 production rate high up to 1874 mu mol g-1 h-1, exceeding most reported photocatalysts under this condition, even comparable to those supported by sacrificial agents and O2. The coordination environment of Cu can be modulated by halogen atoms (X=Cl, Br, I), which in turn affects the electron transfer process and finally determines the reaction activity. This is the first time that 2D CPs have been used for photocatalytic H2O2 production in such challenging conditions, which provides a new pathway for the development of portable in situ H2O2 photosynthesis devices. Two-dimensional coordination polymers CuX-dptz were synthesized by a rapid and facile method at the gram level. CuX-dptz exhibits H2O2 photoproduction activity under pure water and open air without additives through an oxygen reduction process. The microenvironment of the Cu sites can be regulated by halogen atoms, which affects the electron transfer capability and substrate accessibility, and ultimately determines the catalytic activity.image