Realization of photocatalytic hydrogen production by optimizing energy band structure and promoting charges separation over the S-doped CoFe2O4 microrods

As a green, renewable, and clean energy acquisition technology, photocatalytic water splitting to produce hydrogen exhibits high potential in the efficient utilization of solar energy. Herein, S-doped CoFe2O4 microrods were prepared by a simple water bath sulphuration method. The characterization results show that with the increase of S-element doping, the optical absorption and charge separation efficiency of CoFe2O4 microrods are significantly improved. In addition, the upward shift of conduction band (CB) after sulphuration in S-doped CoFe2O4 promotes its optical reduction potential to increase, and then can achieve the photocatalytic water splitting to produce hydrogen without any cocatalyst. Density functional theory (DFT) calculations also confirm that the doping of S in CoFe2O4 can adjust the band structure, promote the upward shift of CB, and accelerate the carrier separation efficiency. These findings suggest the infinite potential of S-doped CoFe2O4 photocatalyst and solar energy for water splitting.