1D/2D constructed Bi2S3/Bi2O2CO3 direct Z-Scheme heterojunction: A versatile photocatalytic material for boosted photodegradation, photoreduction and photoelectrochemical detection of water-based contaminants

In this work, two-dimensional Bi 2 O 2 CO 3 disk is synthesized, followed by the growth of Bi 2 S 3 over Bi 2 O 2 CO 3 via topotactic transformation by controlling the amount of thiourea under hydrothermal conditions. The synthesized composite catalyst is investigated for photocatalytic oxidation and reduction of tetracycline hydrochloride and hexavalent chromium under visible light irradiation. High interfacial contact between the Bi 2 O 2 CO 3 disk0 and Bi 2 S 3 fiber is confirmed via high-resolution microscopic imaging. Enhanced light absorption and increased charge carrier separation is observed after the formation of the Bi 2 S 3 /Bi 2 O 2 CO 3 composite. The Bi 2 S 3 /Bi 2 O 2 CO 3 composite grown using 1 mmol of thiourea shows approximately 98% degradation of tetracycline hydrochloride after 120 min and 99% Cr(VI) reduction after 90 min of photochemical reaction under visible light irradiation. The charge separation is due to the formed internal electric field at the interface, which upon light irradiation follows a z-scheme charge transfer hindering the recombination at the Bi 2 S 3 and Bi 2 O 2 CO 3 interface, thereby contributing efficiently to the photochemical process. In addition, the mechanism of the photochemical reaction for the degradation of pollutants is supported using quencher and probe experiments. Furthermore, photoelectrochemical detection of antibiotic in aqueous solution is conducted to understand the sensing feasibility of the synthesized system. • 1D/2D Bi 2 S 3 /Bi 2 O 2 CO 3 photocatalytic system developed by topotactic transformation. • Growth of 1D fiber-like Bi 2 S 3 is governed by amount of thiourea in precursor. • 98% T-HCl and 99% Cr(VI) degradation is observed in 120 and 90 min, respectively. • ·OH radicals along with superoxide radicals played major role in photocatalysis. • PEC detection of T-HCl shows LOD to be 0.15 ppb with linearity in 0.01–100 ppb.