Microstructure regulation and photocatalytic H2 evolution mechanism of novel MCNTs-Zn0.3Cd0.7S/Pd composites

Zinc cadmium sulfide solid solution as a photocatalytic material has the advantages of narrow band gap and suitable conduction band potential, but the fast rate of photogenerated electron-hole recombination is a non-negligible problem. Inspired by the efficient transfer of bioelectric current between neuronal cells, we achieved the modulation of 1% MCNTs-Zn 0.3 Cd 0.7 S microscopic morphology by regulating the ratio of oleic acid and oleylamine during the hydrothermal process, and further constructed the photogenerated carrier transport pathway through the introduction of Pd to improve the rate of hydrogen production from photolytic water. The results showed that the addition of oleic acid and oleylamine resulted in higher crystalline aggregation and smaller peripheral size of the composite materials. The incorporation of both carbon nanotubes and Pd gives the composite's a high photoresponse as well as a low impedance. These are reflected in the photocatalytic hydrogen production rate: the photocatalytic hydrogen production rate of 1% MCNTs-Zn 0.3 Cd 0.7 S/4% Pd reaches 3.889 mmol/g/h, and its photocatalytic rate is 8.89 times higher than that of Zn 0.3 Cd 0.7 S.