Enhanced CO2 photocatalytic conversion into CH3OH over visible-light-driven Pt nanoparticle-decorated mesoporous ZnO-ZnS S-scheme heterostructures

In the present contribution, the design and fabrication of Pt nanoparticle-decorated mesoporous ZnO-ZnS heterostructures were described and used effectively for photocatalytic CO2 conversion to yield CH3OH. TEM images of the mesoporous Pt/ZnS-ZnO heterostructure demonstrated spherical ZnO NPs similar to 20 nm, and Pt NPs similar to 3 nm were well dispersed on the porous ZnS-ZnO heterostructure. The formation of CH3OH over the Pt/ZnS-ZnO heterostructure was 78, 39 and 20 times larger than that bare ZnS, ZnO NPs and ZnS-ZnO, respectively. The optimal Pt/ZnO-ZnS heterostructure exhibited a high CH3OH formation rate of 81.1 mu molg(-1)h(-1), which is about 44, 22 and 20 times larger than that of bare ZnS (1.86 mu molg(-1)h(-1)), ZnO (3.72 mu molg(-1)h(-1)), and ZnO-ZnS (4.15 mu molg(-1)h(-1)), respectively. The significantly enhanced reduction of CO2 was imputed to the synergistic effects of the ZnO-ZnS heterostructure and the incorporation of Pt NPs. The synthesized photocatalyst provides a new transfer route through which carriers can migrate to the outer surface as well as pore channels of the mesoporous ZnO-ZnS, therefore significantly minimizing the transfer distance for carriers, inhibiting photoinduced electron-hole recombination, and diminishing the mobility resistance, as determined using photoluminescence, photo-current response, and electrochemical impedance spectra measurements.

Automated summary

The design and fabrication of Pt nanoparticle-decorated mesoporous ZnO-ZnS heterostructures were described and used effectively for photocatalytic CO2 conversion to yield CH3OH. The significantly enhanced reduction of CO2 was attributed to the synergistic effects of the ZnO-ZnS heterostructure and the incorporation of Pt NPs. The synthesized photocatalyst provides a new transfer route through which carriers can migrate to the outer surface as well as pore channels of the mesoporous ZnO-ZnS, thereby significantly minimizing the transfer distance for carriers and inhibiting photoinduced electron-hole recombination.