Developing A Novel Method for H2O2 Production via Integration of Photocatalysis and Underwater Friction

Abstract

Hydrogen peroxide (H2O2) is a commodity chemical, an environmentally friendly oxidant and difficult to synthesize commodity chemical, but its production in industry is restricted to a hazardous, energy-intensive, anthraquinone auto-oxidation (AO) process, which is economically feasible only when used inexpensively at large scales and is highly waste producing in terms of organic products. This semicentral model of production requires a transport of highly concentrated, and therefore dangerous, H2O2 solutions. This thesis proposes a new direction and a decentralized method towards the sustainable production of hydrogen peroxide through synergistic combination of photocatalysis and underwater mechanical energy, i.e. friction and sonication to tackle these economic, environmental and safety issues. The proposed methodology does not need the hazardous chemical inputs, and it is conducted in ambient conditions. The essence of the research work was in uniform study of a composite system in suspension (glass powder, or quartz, and polytetrafluoroethylene, or PTFE, particles in water), which undergoes both UV treatment and intense probe sonication. The synergetic mechanism assumed in the study is as follows: photocatalysis of the semiconductor material itself would transform to the electron-hole pair generation process, and mechanical energy addition would play several important roles (1) stimulating the process of charge separation and migration, including the triboelectric effect, and the piezoelectric effect on the surface of the material; (2) producing more radical precursors (or •OH) owing to sonolysis and acoustic cavitation; and (3) creating active surfaces and reducing mass transfer limitations occurring continually. To maximize the process a complete parametric study was made that would analyze the effects of various material concentrations, reaction time, temperature and the effect of sonication itself in a systematic manner. Conclusively, the results indicate that H2O2 was successfully produced, and a yield of sufficient increase was realized when sonication was added, which is the apparent validation of the proposed synergistic effect of improvement. The best conditions were found, and the process had shown a high degree of reproducibility, which proves the advantageousness of the practice. Successfully developed a novel, dual-energy ix system for sustainable H₂O₂ production, achieving a maximum yield of 5.48 mgh⁻¹cm⁻² under optimized conditions (120 min, 25g glass + PTFE, 22-26°C). The present work presents the main concept of a novel dual-energy target design that uses the forces of both light and mechanical energy as a source of chemical synthesis. The results mark a milestone in the establishment of green, on-site, and on-demand technologies of producing H2O2 and the potential applications that utilize this concept are monumental like water treatment and disinfection.