Replacing sluggish oxygen evolution reaction (OER) with hydrazine oxidation reaction (HzOR) to produce hydrogen has been considered as a more energy-efficient strategy than water splitting. However, the relatively high cell voltage in two-electrode system and the required external electric power hinder its scalable applications, especially in mobile devices. Herein, we report a bifunctional P, W co-doped Co₃N nanowire array electrode with remarkable catalytic activity towards both HzOR (−55 mV at 10 mA cm⁻²) and hydrogen evolution reaction (HER, −41 mV at 10 mA cm⁻²). Inspiringly, a record low cell voltage of 28 mV is required to achieve 10 mA cm⁻² in two-electrode system. DFT calculations decipher that the doping optimized H* adsorption/desorption and dehydrogenation kinetics could be the underlying mechanism. Importantly, a self-powered H₂ production system by integrating a direct hydrazine fuel cell with a hydrazine splitting electrolyzer can achieve a decent rate of 1.25 mmol h⁻¹ at room temperature.

Partially exposed RuP ₂ on carbon endows outstanding activity to hydrazine oxidation and hydrogen evolution catalysis.

The structural, electronic, and optical properties of a g-C₃N₄(001)/BiVO₄(010) nanocomposite have been investigated using first-principles calculations. The results indicate that g-C₃N₄(001) can stably adsorb onto the BiVO₄(010) surface, and it tends to form a regular wavy shape. The calculated band gap of the g-C₃N₄(001)/BiVO₄(010) nanocomposite is narrower compared with that of BiVO₄ or BiVO₄(010), primarily due to the introduction of N 2p states near the Fermi level. The g-C₃N₄(001)/BiVO₄(010) nanocomposite has a favorable type-II band alignment; thus, photoexcited electrons can be injected into the conduction band of g-C₃N₄(001) from the conduction band of BiVO₄(010). The proper interface charge distribution facilitates carrier separation in the g-C₃N₄(001)/BiVO₄(010) interface region. The electron injection and carrier separation can prevent the recombination of electron–hole pairs. The calculated absorption coefficients indicate an obvious redshift of the absorption edge, which is in good agreement with the experimental results. Our calculation results suggest that the g-C₃N₄(001)/BiVO₄(010) nanocomposite has significant advantages for visible-light photocatalysis.