Incorporating Co ₃ O ₄ /C modified MnO _<i>x</i> /SiO ₂ into tailored sponge for bifunctional photothermal water evaporation and pollutant degradation

Abstract

Abstract In this study, cobalt‐incorporated polydopamine coating onto Mn‐modified mesoporous silica and successive graphitization treatment make the resulting composite afford abundant porosity, multiple metal active species, polar N sites, and excellent light‐to‐heat conversion ability. The controlled graphitization temperature was optimized to improve the activity state of metal species. The results reveal that Co 3 O 4 nanoparticles incorporated thin‐layer carbon formed onto the Mn‐confined mesoporous silica, and more Co(II) and Mn(III) were generated in the MS‐Co‐500N 2 compared to MS‐Co‐500Air, which could cause the accelerated reaction cycles in the potassium peroxymonosulfate complex salt (PMS) activation. The degradation experiments demonstrated that the catalyst almost completely degraded biphenol A within 10 min with the reaction rate constant of 0.56 min −1 , nearly 205 times enhancement compared to the MS‐Co‐500Air. The free radicals trapping and quenching control demonstrated the dominant role of 1 O 2 and ·O 2 in the degradation process. Due to the efficient incorporation of Co 3 O 4 nanoparticles and thin‐layer carbon, the photothermal conversion properties were explored and utilized for solar‐driving interface water evaporation and cleanwater recovery. To explore the practical application possibility in treating complicated polluted wastewater, the MS‐Co‐500N 2 materials were fixed on the melamine sponge by Ca ions‐trigger alginate crosslinking strategy, and the integrated monolith evaporator shows an excellent water evaporation performance (1.52 kg·m −2 ·h −1 ) and synchronous pollutant removal in biphenol A (94%, 10 min), carbamazepine (92%, 10 min), oxytetracycline (84%, 20 min) and norfloxacin (84%, 20 min).