Carbon cloth supported black phosphorus-FeMoO₄ composites for peroxymonosulfate-assisted photoelectrocatalytic degradation of tetracycline hydrochloride

This research utilized the solvothermal technique to prepare carbon cloth supported black phosphorus-FeMoO4 (CC-BP-FMO) composites, which were used for the degradation of tetracycline hydrochloride (TC-HCl) through the peroxymonosulfate (PMS)-assisted photoelectrocatalysis (PEC) route. Several characterization techniques were employed to systematically examine the morphology, elemental composition, crystal and molecule structures, magnetism properties, bonding states, energy band structure, separation efficiency of photo-induced carriers, electrochemical behaviors, reactive species, and intermediate products of TC-HCl degradation. The experimental results demonstrated that the performance of PMS-assisted PEC TC-HCl degradation by the CC-BP-FMO composites was significantly improved in comparison with photocatalysis, electrocatalysis, PMS activation, and PEC. The CC-BP-FMO composites with more exposed BP-FMO catalysts exhibited the ability to be reused for PMS-assisted PEC degradation of TC-HCl, with a large k value of 0.21 min−1 and a high degradation rate of 97% after the fourth cycle. The remarkable PMS-assisted PEC property of the CC-BP-FMO composites was mainly attributed to the swift separation of photo-induced charge carriers, which hastened the creation of reactive radicals. Five possible catalytic reaction pathways existed in the CC-BP-FMO composites towards TC-HCl degradation under the PMS-assisted PEC condition. Importantly, the photo-generated electrons and [Formula: see text] radicals were advantageous for the redox reaction of Fe+2/Fe+3 and Mo+4/Mo+6. The oxygen vacancies caused by P and Mo in the BP-FMO heterojunction could suppress the carrier recombination. The degradation of TC-HCl involved the participation of oxygen vacancy, [Formula: see text], [Formula: see text], and ∙OH radicals, and 1O2 nonradicals. The CC-BP-FMO composites have the potential application for treating wastewater containing organic pollutants.