A sulfide self-driven fuel cell for H2O2 electrosynthesis and sulfur recycling

An energy-free method is developed to produce H2O2 directly from air and sulfur from sulfide-contained wastewater simultaneously. The sulfide self-driven fuel cell can recycle chemical energy into electric energy and sulfide contaminants to sulfur. The H2O2 electrosynthesis strategy is no need for external energy or fuels, which is driven by the electrical energy from sulfide pollutants oxidation. The fuel cell exhibits excellent battery performances, e.g. the highest open cell voltage of 1.29 V and a running current of >100 mA cm(-2) at 0 V. The initial current efficiency for H2O2 is 97.94 +/- 1.85 %. For wastewater and air tests, the fuel cell can produce 24.75 +/- 0.35 mmol L-1 H2O2 solution within 10 h, with an average productivity of 0.37 +/- 0.03 mmol cm(-2) h(-1). It not only can recover the resource and energy from pollutants but also reduce the production energy consumption. The excellent two-electron route oxidation performances of sulfide are proven using in-situ electrochemical technology. This attempt can shed light on H2O2 electrosynthesis and the recycling of sulfide-contained wastewater.

Automated summary

An energy-free method has been developed to produce H2O2 from air and sulfur from sulfide-contained wastewater using a sulfide self-driven fuel cell. This fuel cell exhibits excellent battery performances and can produce H2O2 without the need for external energy.