Establishing Z-scheme Bi2WO6/g-C3N4 interfaces toward efficient photocatalytic performance of NOx under visible light

NOx gas is released from automobile emissions and fossil fuel combustion. The photocatalytic method was applied to address environmental issues, notably NOx air pollution because of environmentally friendly, low cost, and utilized solar light irradiation. In this work, a Z-scheme Bi2WO6/g-C3N4 heterojunction photocatalyst was successfully synthesized by a hydrothermal method at 180 degrees C for 12 h. Combining g-C3N4 with Bi2WO6 promoted two oxidation (over Bi2WO6) and reduction (over g-C3N4) sites, enhancing the photocatalytic activity of the g-C3N4 single-component system. The sample contains 20 wt% of Bi2WO6, becoming the best excellent photocatalytic activity at approximately 43.45% in 30 minutes of visible light irradiation. In addition, the photogenerated electron (e(-)) and hole (h(+)) were determined as primary agents. The high stability of Bi2WO6/g-C3N4 photocatalysts was demonstrated by little change in photocatalytic performance over five cycles of photocatalytic measurements. The NOx removal mechanism and the intermediate generation were proposed to understand the reaction process better.