High-efficiency electrochemical decomposition of artificial sweetener aspartame using a Ti3+ self-doped TiO2 nanotube arrays anode

Artificial sweeteners have attracted growing concern considering their large usage, wide detection and ecological toxicity in the last decade. In this work, high-efficiency decomposition of artificial sweetener aspartame was investigated by using a Ti3+ self-doped TiO2 nanotube arrays electrode. Effects of current density, initial concentration and inorganic anions on the degradation kinetics were studied. Results showed that the electrochemical degradation of aspartame followed pseudo-first-order kinetics, and the rate constant was 0.039 min(-1) at a current density of 2 mA cm(-2). The electrochemical degradation was not susceptible to nitrate, and the degradation was significantly enhanced by chloridion. Twenty-four transformation products were identified by UPLC-Orbitrap-MS/MS, and possible electrochemical degradation pathway was proposed. The degradation process of aspartame mainly included hydroxylated, demethylation, dehydrogenation, dehydration condensation and side-chain cleavage. Quantitative structure-activity relationship model revealed that the potential risks in electrolysis process should not be ignored before complete mineralization of aspartame. Energy consumption was greatly reduced in the presence of Cl-, and the lowest value for 90% aspartame degradation was 0.07 Wh L-1 . The findings presented here demonstrate that electrocatalysis exhibits high efficiency in degrading aspartame and is potentially suitable for eliminating artificial sweeteners from wastewaters.

Automated summary

Artificial sweeteners, particularly aspartame, have raised concerns due to their widespread use and ecological toxicity. This study investigated the efficient decomposition of aspartame using a Ti3+ self-doped TiO2 nanotube arrays electrode. The results showed that electrocatalysis was highly effective in degrading aspartame, with potential for removing artificial sweeteners from wastewater.