Plasma Bombardment and Heterodoping Induced Abundant Reactive Sites and Sturdy Structure for Efficient Electrooxidation of 5-Hydroxymethylfurfural and Hydrogen Production

The 5-hydroxymethylfurfural oxygen reaction (HMFOR) is an appealing alternative to the oxygen evolution reaction (OER) for cost-effective hydrogen production, while 2,5-furandicarboxylic acid (FDCA) represents one of the most promising value-added chemicals. Nevertheless, it still suffered from limited HMF adsorption and sluggish reaction kinetics. Herein, we integrated the low-temperature microwave method and plasma bombardment strategy, and developed an advanced P/Mn–Ni(OH)2 nanosheet array on the surface of carbon cloth. The heterogeneous Mn dopant improves the growth and structural stability of Ni(OH)2 nanosheet arrays, while the plasma treatment optimizes the atomic sequence and induces abundant oxygen vacancies. Further theoretical calculation and in situ Raman, Bode diagram tests manifest that these oxygen vacancies together with the Mn dopant, coherently downshift the d-band center of P/Mn–Ni(OH)2 (from −3.71/–0.31 eV (spin-up/spin-down) to −5.23/–1.78 eV, respectively), balance the adsorption of HMF and OH–, and enhance the redox kinetics of HMFOR. Benefiting from these favorable factors, the P/Mn–Ni(OH)2 achieves remarkable HMFOR electrocatalytic activity, with an impressive HMF conversion rate of 99.8%, FDCA selectivity of 97.4%, and Faraday efficiency of 96.1% at an applied potential of 1.42 V (vs RHE). Meanwhile, the P/Mn–Ni(OH)2 also demonstrates robust stability with only slight decay after five cycles of testing. When further coupled with HER, the assembled HER||HMFOR electrolyzer requires only 1.35, 1.46, and 1.57 V to deliver 10, 50, and 100 mA cm–2, respectively, outperforming the traditional HER||OER device (requesting 1.55, 1.65, and 1.70 V, respectively), confirming the brilliant electrocatalytic ability of the P/Mn–Ni(OH)2. Such plasma bombardment and heterogeneous atom implantation comodulated electrocatalytic strategy may provide new insight into the construction of advanced catalysts for diverse energy-related applications.