Controlled Construction of Copper Phthalocyanine/α-FeO Ultrathin S-Scheme Heterojunctions for Efficient Photocatalytic CO Reduction under Wide Visible-Light Irradiation.

The wide visible-light-driven CO reduction to acquire solar fuels is a highly desired green route. Herein, novel ultrathin copper phthalocyanine (CuPc)/α-FeO heterojunctions as efficient wide visible-light-driven photocatalysts for CO reduction are controllably synthesized by the hydroxyl-induced self-assembly of CuPc onto ultrathin α-FeO as-pre-prepared through an Al-regulated hydrothermal method. The optimized CuPc/FeO heterojunction exhibits about 15-fold high photoactivity for reducing CO to CO and CH compared with reported FeO nanoparticles. The exceptional photoactivity is mainly attributed to the enhanced S-scheme charge transfer and separation in the resulting closely contacted heterojunction, the extended visible-light range from molecularly disperse CuPc, and its provided central metal cation (Cu) with favorable catalytic function for CO activation, mainly by means of the dual-wavelength photocurrent action spectra, the electrochemical reduction tests, and the in situ diffuse reflectance infrared Fourier transform spectra (DRIFTS). This investigation provides new insight about designing and constructing novel metal phthalocyanine (MPc)-involved S-scheme heterojunction photocatalysts.