Monocrystal Ni₂O₃H/Sb₂O₃ Heterojunction for Energy-Saving Hydrogen Evolution Linking to Generation of...

Energy crisis coupling environmental pollution caused by biomass is becoming global issues. Electrocatalytical water splitting to produce H₂ and upgrading 5-hydroxymethylfurfural (HMF) as 2,5-furandicarboxylic acid (FDCA) is a "one stone two birds" way to solve these problems in the meantime. Herein, the 0.5Ni₂O₃H/0.5Sb₂O₃ heterojunction was synthesized as a bifunctional electrocatalyst for hydrogen evolution reaction (HER) and electrocatalytic HMF oxidative reaction (HMFOR), to utilize the design concept that the Ni₂O₃H is in charge of HMFOR, and the Sb₂O₃ is in charge of HER. The 0.5Ni₂O₃H/0.5Sb₂O₃ shows the outstanding performances with the HMFOR potential of 1.39 V and the HER potential of 129 mV at 10 mA cm^-2 in 1 M KOH + 0.1 M HMF. Meanwhile, the HMF is oxidized as FDCA through the 5-hydroxymethyl-2-furancarboxylic acid pathway according to the in situ electrochemical Attenuated Total Reflectance-Infrared Spectroscopy results, and the selectivity is up to 99.6% and the Faradaic efficiency is 95.5% at 1.3 V. This work provides a facile strategy to design a universal Sb-based heterojunction for electrocatalytic HER and HMF oxidation to generate FDCA.