Molecular modulation of interfaces in a Z-scheme van der Waals heterojunction for highly efficient photocatalytic CO 2 reduction

The construction of van der Waals (vdW) heterojunctions is a key approach for efficient and stable photocatalysts, attracting marvellous attention due to their capacity to enhance interfacial charge separation/transfer and offer reactive sites. However, when a vdW heterojunction is made through an ex-situ assembly, electron transmission faces notable obstacles at the components interface due to the substantial spacing and potential barrier. Herein, we present a novel strategy to address this challenge via wet chemistry by synthesizing a functionalized graphene-modulated Z-scheme vdW heterojunction of zinc phthalocyanine/tungsten trioxide (xZnPc/yG-WO ). The functionalized G-modulation forms an electron "bridge" across the ZnPc/WO interface to improve electron transfer, get rid of barriers, and ultimately facilitating the optimal transfer of excited photoelectrons from WO to ZnPc. The Zn in ZnPc picks up these excited photoelectrons, turning CO into CO/CH (42/22 μmol.g .h ) to deliver 17-times better efficiency than pure WO . Therefore, the introduction of a molecular "bridge" as a means to establish an electron transfer conduit represents an innovative approach to fabricate efficient photocatalysts designed for the conversion of CO into valued yields.