Sustainable Hydrogen Peroxide Synthesis Using Bismuth-Modified Biochar

Abstract

In this work a novel biochar based renewable electrode material has been developed for the sustainable electrochemical synthesis of hydrogen peroxide via oxygen reduction. Biochar was derived from waste, Himalayan poplar wood (Populus ciliata) through pyrolysis at (600-1000^oC). The obtained biochar was characterized by using techniques, like scanning electron microscopy (SEM) to investigate morphology, X-ray diffraction (XRD) to analyze crystal structure and degree of graphitization and Raman spectroscopy to probe internal structure. The results affirmed that the biochar obtained from poplar wood was highly porous and containing both ordered and disordered carbon framework. This biochar was further ball milled with bismuth carbonate and annealed at 600^oC to get bismuth doped biochar. The XRD spectra revealed the successful incorporation of bismuth in the carbon framework of biochar.  The results of electrochemical impedance spectroscopy (EIS) showed that the bismuth doped biochar has less equivalent series resistance compared to pristine biochar. Incorporating bismuth into biochar resulted in a current density of 1.1 mA/cm², exceeding the 0.5 mA/cm² achieved by undoped biochar. Moreover, the bismuth-doped biochar exhibited greater selectivity of 71.25% compared to 49.6% for the pristine biochar. These findings hold good promise for bio waste utilization to develop ecofriendly electrode material for onsite, on demand synthesis of hydrogen peroxide.