Higher hydrogen production by photocatalytic water splitting using a hollow tubular graphitic carbon nitride-zinc telluride composite

Energy demand and pollution due to urbanization and industrialization are calling for clean energies such as dihydrogen (H₂) obtained by water splitting. For that, zinc telluride is a promising semiconductor having a narrow bandgap that can absorb a large amount of visible light and promotes the separation of charge carriers. Here, we prepared a 1D hollow tubular graphitic carbon nitride (g-C₃N₄) composite (h-CN) by a precipitation using melamine as a precursor. Results show that composite produces higher yields of dihydrogen, of 11,188 μmol g⁻¹ h⁻¹, than with ZnTe, of 8331 μmol g⁻¹ h⁻¹, and with h-CN, of 1012 μmol g⁻¹ h⁻¹. Furthermore, the new modified heterojunction displays quantum efficiency of about 17.1% at 420 nm, which is much higher than for h-CN, of 0.87%, and for ZnTe, of 7.29%. Higher performances are explained by reducing the charge recombination and increasing the transfer of electrons by creating a strong p-n heterojunction. An advantage of the new photocatalyst is that it does not require an expensive noble metal.