In-situ electrosynthesis of hydrogen peroxide and wastewater treatment application: A novel strategy for graphite felt activation

Electrochemical synthesis of hydrogen peroxide (H2O2) through O-2 electroreduction is an attractive alternative to the currently used anthraquinone process, and highly desirable for green chemical industries and environmental remediation. However, it remains a great challenge to develop cost-effective and durable electrocatalysts. Hence, rational strategy for developing electrocatalyst materials to achieve highly efficient 2e(-) pathway oxygen reduction reaction (ORR) electrocatalysis is extremely important for in situ electrochemical synthesis of H2O2. In the present work, an economical activated graphite felt (AGF) material, following a simple and low-cost gaseous acetic acid activation method, is developed. With this activation process, the electrochemical performance of the AGF shows a great promotion for H2O2 production rate. Compared with raw graphite felt (RGF) material, the yield of H2O2 achieved on AGF is enhanced by several folds. The enhanced performance might be attributed to its specific pore structure, high content of defects and transformation of surface chemical bonds, which derives from the activation with gaseous acetic acid at high temperature. It is found that the factors responsible for the remarkable electrocatalytic performance of AGF1100 are: 1) the special pore structure, which offers large area for reaction, obtained through gaseous acetic acid activation process at high temperature; 2) high content of sp(3)-C bonds, defects, and oxygen-containing functional groups, which can act as active sites for oxygen adsorption or reduction during the electrocatalytic process.