Superior performance of oxygen vacancy-enriched Cu-Co3O4/urushiol-rGO/peroxymonosulfate for hypophosphite and phosphite removal by enhancing singlet oxygen

• Published in: Journal of colloid and interface science 2024-06, Vol.663, p.177-190
• Main Authors: Wan, Yali, Li, Zhongkai, Zheng, Xuelin, Pan, Danmei, Wu, Haobin, Lu, Xin, Ding, Sibo, Lin, Liangxu
• Format: Article
• Language: English
• Subjects: Graphene; nanoparticles; organic phosphorus; oxidation; oxygen; Oxygen vacancy; Peroxymonosulfate activation; phosphates; Phosphorus-containing wastewater; pollution; singlet oxygen; Urushiol; wastewater; wastewater treatment
• ISSN: 0021-9797; 1095-7103
• DOI: 10.1016/j.jcis.2024.02.149

[Display omitted] The treatment of wastewater containing hypophosphite [P(I)] and phosphite [P(III)] is challenged by limitations of traditional Fenton oxidation such as low efficiency, secondary pollution and high costs. This study introduced a facile solvent-thermal method to synthesize Cu-Co3O4 nanoparticles uniformly loaded on graphene (Cu-Co3O4/U-rGO) through the reduction and coordination effects of urushiol (U). As prepared Cu-Co3O4/U-rGO exhibited excellent activity in activating peroxymonosulfate (PMS) for the oxidation of P(I)/P(III) to phosphate [P(V)] (0.229 min−1), along with high stability and reusability (91.5 % after 6 cycles), low metal leaching rate (Co: 0.2 mg/L, Cu: 0.05 mg/L), insensitivity to common anions in water and a wide pH range (3–11). The activation mechanism involved the synergistic effects from both urushiol and graphene, which promoted redox of Cu+/Cu2+ and Co2+/Co3+ and induced abundant oxygen vacancies for PMS activation to produce singlet oxygen. Furthermore, the Cu-Co3O4/U-rGO/PMS was also excellent in the oxidative removal of organic phosphorus. This study is expected to advance strategies for the treatment of P(I)/P(III)-rich wastewater and provide new insights for the development of low-cost, highly efficient heterogeneous catalysts with abundant oxygen vacancies.