Preparation of W₁₈O₄₉/C-TiO₂ direct Z-scheme photocatalyst and photocatalytic water splitting for H₂ production

W18O49/C-TiO2 direct Z-scheme photocatalyst was prepared by a simple hydrothermal method. The structure, morphology, transport properties of photogenerated carriers and energy band structure were characterized by XRD, SEM, TEM, HRTEM, PL and other measurements. Under simulated sunlight illumination, the photocatalytic water splitting performance for hydrogen (H2) production and quantum efficiency were studied without adding any sacrificial agent. The results show that the construction of W18O49/C-TiO2 direct Z-scheme photocatalyst can significantly improve light absorption, accelerate the separation and transport of photogenerated carriers, and enable more photogenerated electrons participate in the photocatalytic reduction reaction, so the sample possesses high efficient photocatalytic activity. The photocatalytic H2 production tests show that under simulated sunlight illumination, the W18O49/C-TiO2 direct Z-scheme heterojunction can achieve H2 production rate of 209 μmol·h-1·g-1 without adding any sacrificial agents. It also exhibits strong photocatalytic stability; the H2 production remains unchanged during the 24 h cycle test.