Construction of hierarchical BiPW12O40/BiOI p-n heterojunction with enhanced visible light activity for degradation of endocrine disrupting Bisphenol A

Herein, we report on the efficient visible-light driven BiPW12O40/BiOI (BPWBI) photocatalyst that was prepared by combining different weight percentages of BiPW12O40 (1.0, 3.0, 5.0%) with BiOI via facile one-step wet impregnation method. The prepared BPWBI photocatalysts were characterized by XRD, FTIR, TGA, BET, FESEM, EDS/Mapping, TEM, UV-Vis DRS, and PL. The photocatalytic performance of the materials was assessed for the degradation of Bisphenol A (BPA) under visible light. The optimum composite photocatalyst (1.0BPWBI) exhibited an efficiency of 94.2% on BPA after 120 min at the optimum conditions (catalyst dosage = 20 mg, pH = 6.68, and constant pollutant concentration = 15 mg L-1). In the presence of peroxodisulfate (PDS), the efficiency was improved to 98.7% in 80 min whereas the efficiency was drastically reduced in the presence of acid blue 25 (AB 25) dye. Photoluminescence (PL) measurements, confirmed that 1.0BPWBI exhibited enhanced electron-hole separation and slow recombination rate of electron-hole pairs. The trapping experiments deduced that h(+), and O-2(-) were the most active species responsible for the degradation of BPA. Moreover, the photodegradation pathway was hypothesized based on the LC-MS results on transformation products in the presence of 1.0BPWBI. The impressive photocatalytic performance and stability proved that 1.0BPWBI catalyst renders itself as a promising and valuable photocatalyst for wastewater treatment and can be further explored in the degradation of other organic pollutants for environmental remediation.