Solar-Driven Syngas Production Using Al-Doped ZnTe Nanorod Photocathodes

Syngas, traditionally produced from fossil fuels and natural gases at high temperatures and pressures, is an essential precursor for chemicals utilized in industry. Solar-driven syngas production can provide an ideal pathway for reducing energy consumption through simultaneous photoelectrochemical CO2 and water reduction at ambient temperatures and pressures. This study performs photoelectrochemical syngas production using highly developed Al-doped ZnTe nanorod photocathodes (Al:ZnTe), prepared via an all-solution process. The facile photo-generated electrons are transferred by substitutional Al doping on Zn sites in one-dimensional arrays to increase the photocurrent density to -1.1 mA/cm(2) at -0.11 V-RHE, which is 3.5 times higher than that for the pristine ZnTe. The Al:ZnTe produces a minor CO (FE approximate to 12%) product by CO2 reduction and a major product of H-2 (FE approximate to 60%) by water reduction at -0.11 V-RHE. Furthermore, the product distribution is perfectly switched by simple modification of Au deposition on photocathodes. The Au coupled Al:ZnTe exhibits dominant CO production (FE approximate to 60%), suppressing H-2 evolution (FE approximate to 15%). The strategies developed in this study, nanostructuring, doping, and surface modification of photoelectrodes, can be applied to drive significant developments in solar-driven fuel production.

Automated summary

This study investigates photoelectrochemical syngas production using Al-doped ZnTe nanorod photocathodes prepared via an all-solution process. The product distribution can be switched by surface modification, achieving high CO or high H2 production rates. These strategies have significant implications for solar-driven fuel production.