Pt/BiOBr Nanocomposite Supported on Graphdiyne for the Selective Photoreduction of CO₂ into Hydrocarbons

Regulating the electron–hole lifetime would increase the surface charge density of photocatalysts and then promote the photocatalytic conversion of CO2 into hydrocarbons. Herein, Pt and graphdiyne (GDY), respectively, as electron and hole transfer bodies were introduced into a multiple Pt/BiOBr-GDY heterojunction, constructing fast channels of electron and hole transfer and then prolonging their lifetime. Under light irradiation, the Pt/BiOBr-GDY nanocomposite changed the product distribution and significantly allowed the selective photocatalytic CO2 conversion to CH4 and C2 hydrocarbons (C2H4 and C2H6), with the total CxHy selectivity of about 97%. The synergistic effect of Pt and GDY facilitated the separation and transfer of photogenerated electrons and holes on BiOBr, increased the surface charge density, and ultimately improved the efficiency of photocatalytic CO2 reduction. At the same time, due to the characteristics of GDY, it can afford more surface-adsorbed active sites for CO2 and intermediates, thus further improving the photocatalytic efficiency and selectivity. Hence, this work provides an insight into the promotion of the selective photoreduction of CO2 to hydrocarbon products by the synergistic effect of the metal, semiconductor, and GDY.