From brew to clean fuel: harnessing distillery wastewater for electrolysis H2 generation using nano scale nickle selenide water oxidation catalysts

Abstract

This study reports a promising and innovative approach for electrochemical green H₂ generation using distillery industry wastewater. We employed solvothermally derived Ni₂Se₃ nanoparticles with a particle size of ∼50 nm as the anode catalyst material to effectively oxidise the acetic acid present in the distillery wastewater. The utilisation of a Ni₂Se₃ nanoparticle-coated stainless steel electrode significantly enhanced the current density (282 mA cm⁻²) in the electrochemical cell compared to the pristine SS (stainless steel) electrode (146 mA cm⁻²) at 2 V RHE. Also, the distillery wastewater electrolyte based cell exhibits higher current density compared to conventional freshwater (i.e., NaOH-based) electrolyte. The distillery wastewater electrolyte demonstrated remarkable H₂ gas evolution (∼15 mL h⁻¹ cm⁻²), showcasing its potential for sustainable H₂ generation. However, it was observed that the aggressive bubbling effect at the cathode led to a lower H₂ evolution reaction activity when compared to the freshwater-based electrolyte, which displayed a H₂ production rate of ∼22 mL h⁻¹ cm⁻². These findings underscore the potential of employing Ni₂Se₃ as an effective oxidation catalyst in the production of H₂ gas from pre-treated brewery wastewater H₂ gas. The utilisation of Ni₂Se₃ nanoscale water oxidation catalysts in this context opens up new possibilities for both wastewater treatment and H₂ production, paving the way for a more sustainable and resource-efficient future.