Design of noble metal-free CoTiO3/Zn0.5Cd0.5S heterostructure photocatalyst for selective synthesis of furfuraldehyde combined with H2production

The development of photocatalytic systems composed of earth-abundant metal-based catalysts for efficient production of clean fuel, H2 as well as value-added chemicals is of significant importance towards sustainable generation of energy resources. Consequently, herein we report rational construction of Z-scheme CoTiO3/xZn0.5Cd0.5S (x = 5 (S1), 10 (S2), 15 (S3) and 20 wt% (S4)) heterostructures featuring suitable band structure for efficient photocatalytic reduction of protons of water to H2 combined with selective oxidation of furfuryl alcohol (biomass derivative) to a value-added product, furfuraldehyde. Electron microscopy analysis of heterostructure S2 revealed that Zn0.5Cd0.5S nanoparticles are decorated over the surface of CoTiO3 microrods. The photocatalytic studies showed higher catalytic performance by S2, for selective oxidation of furfuryl alcohol to furfuraldehyde with 95% yield coupled with a H2 generation rate of 1929 μmol g-1h-1 which is about 4-fold higher than that of pristine Zn0.5Cd0.5S. The enhanced catalytic performance of heterostructure S2 has been ascribed to synergistic interaction aided by the Z-scheme heterojunction formation between CoTiO3 and Zn0.5Cd0.5S. Overall, this work demonstrates the application of noble metal-free photocatalyst for simultaneous production of H2 and value-added chemical under mild and environment-friendly conditions.