Preparation of a novel Ce and Sb co-doped SnO2 nanoflowers electrode by a two-step (hydrothermal and thermal decomposition) method for organic pollutants electrochemical degradation

Abstract

Nanostructured Sb-SnO2 electrodes with high electrochemical activity and stability are urgently desired for electrochemical oxidation of refractory organics in wastewater treatment, yet hard to be controlled and synthesized. Hence, we combined the hydrothermal method and thermal decomposition technologies to prepare a novel Ce and Sb co-doped SnO2 nanoflowers electrode (Ti/Ce-Sb-SnO2NFs). The incorporation of Ce endowed the Ti/Ce-Sb-SnO2NFs anode with an increased oxygen evolution over-potential (OEP) (1.99 V vs.SCE), lower charge transfer resistance (7.54 Ω⋅cm2), large specific electrochemical active surface area (141.83), a great number of active sites and superior •OH generation ability. Consequently, nearly 100% decolorization efficiency and 91.45% chemical oxygen demand (COD) mineralization efficiency of methylene blue (MB) (20 mg/L) were achieved by the Ti/Ce-Sb-SnO2NFs anode within 90 min. Additionally, the Ti/Ce-Sb-SnO2NFs anode stability was also improved with a longer accelerated lifetime (15.5 h) than the given Ti/Sb-SnO2NFs electrode (8.2 h). We also prepared other nanostructured (nanoparticles, nanoclusters and nanosheets) Sb-SnO2 electrodes with high oxidation capacity utilizing this two-step method, which demonstrated its great versatility. Accordingly, this work could provide a new strategy for fabricating efficient and stable rare earth elements (Ce, Nd, La, etc.) and Sb co-doped SnO2 nanostructured electrodes for decomposition organic pollutants in the field of wastewater treatment.