Novel dual Z-scheme Bi/BiOI-Bi2O3-C3N4 heterojunctions with synergistic boosted photocatalytic degradation of phenol

Photocatalysis is an emerging technique for the remediation of refractory organic contaminants. Herein, a novel dual Z-scheme Bi/BiOI-Bi2O3-C3N4 heterojunctions were constructed through a calcining process following with I- etching and UV-reduction processes. Various analytical technologies were adopted to characterize the materials. As a result, the Bi-0 decorated composite presented improved visible-light-response and rapid charge transfer. Due to the synergy of Bi-0 and dual Z-scheme heterostructures, a remarkable photocatalytic performance toward phenol degradation was achieved with the highest degradation efficiency of 93.2% and rate constant of 0.0161 min(-1) over the optimal composite within 75 min of visible light irradiation. Interestingly, the concen-tration of the yielded benzoquinone considerably decreased with the introduction of C3N4. Trapping experiments and electron spin resonance (ESR) tests indicated that h(+), O-2(center dot-), (OH)-O-center dot and e(-) contributed to phenol remediation, and h(+) and O-2(center dot-) were the crucial species toward phenol degradation. Furthermore, outstanding stability was obtained only with a decline of 3.8% after 4 cycles. A reasonable charge transfer mechanism was also proposed. This work provides a new route for in situ construction of Bi-0 decorated dual Z-scheme heterojunction for phenolic compounds degradation.

Automated summary

A novel dual Z-scheme Bi/BiOI-Bi2O3-C3N4 heterojunctions were successfully constructed for the photocatalytic degradation of phenolic compounds. The composite exhibited improved visible-light-response and rapid charge transfer, leading to a remarkable photocatalytic performance.