Ternary rGO decorated W18O49 @g-C3N4 composite as a full-spectrum-responded Z-scheme photocatalyst for efficient photocatalytic H2O2 production and water disinfection

Integrating g-C 3 N 4 with narrow-band semiconductor to construct a Z-scheme structured heterojunction has been regarded as a common strategy to improve the photocatalytic performance of g-C 3 N 4 . However, limited catalytic activity increment is achieved due to the contradiction of expanding the light absorption scope of traditional photo-oxidation semiconductors (PS II) and preserving their valance band oxidative abilities. Herein, to extend the light absorption range of g-C 3 N 4 based Z-scheme photocatalyst to the whole solar spectra while without losing the high oxidative ability of this system, we select the heavy doped W 18 O 49 as PS II and provide a facile in situ hydrothermal method to elaborately fabricate an rGO decorated W 18 O 49 @g-C 3 N 4 (r-CNW) Z-scheme photocatalyst. The prepared r-CNW-2 (with optimal W 18 O 49 to g-C 3 N 4 weight ratio of 1:2) exhibits improved photocatalytic performance with H 2 O 2 generation rates of 71, 58.5 and 6.3 μmol g −1 h −1 obtained under the simulated solar light, visible light (>400 nm) and NIR light (>800 nm) irradiation, respectively, which is 1.3 and 2 times higher than those of the g-C 3 N 4 counterparts (54, 29 μmol g −1 h −1 and even not detected).such outstanding performance of r-CNW-2 could be associated with the broader light absorption, fast charge separation, and rapid redox reactions. Moreover, the r-CNW-2 also displays an excellent E-coli inactivation activity, comparable to most g-C 3 N 4 -based photocatalysts. Our work gives a new insight through trading off light absorption and redox ability to fabricate efficient Z-scheme photocatalyst for photocatalytic H 2 O 2 generation and environmental remediation.