Xuechun Sun’s research while affiliated with Tianjin University and other places

Cost‐effective, highly efficient and stable non‐noble metal‐based catalysts for the oxygen evolution reaction (OER) are very crucial for energy storage and conversion. Here, an amorphous cobalt nickel phosphate (CoNiPO4), containing a considerable amount of high‐valence Ni³⁺ species as an efficient electrocatalyst for OER in alkaline solution, is reported. The catalyst was converted from Co‐doped Ni2P through pulsed laser ablation in liquid (PLAL) and exhibits a large specific surface area of 162.5 m² g⁻¹ and a low overpotential of 238 mV at 10 mA cm⁻² with a Tafel slope of 46 mV dec⁻¹, which is much lower than those of commercial RuO2 and IrO2. This work demonstrates that PLAL is a powerful technology for generating amorphous CoNiPO4 with high‐valence Ni³⁺, thus paving a new way towards highly effective OER catalysts.

Developing low‐cost, highly active, and stable bi‐functional oxygen reduction and evolutionreaction (ORR/OER) electrocatalysts for rechargeable metal‐air batteries has been regarded as a primary challengefor sustainable energy devices. Herein, for the first time we design and fabricate defective carbon nanotubes (CNTs) enriched with pyridinic nitrogenvia laser irradiation for oxygenelectrocatalysis. Mesopores with plentiful edges are produced on the surface of CNTs, which not only facilitate mass transfer throughout CNTs architecture, but also are favorable for the incorporation of pyridinic nitrogen serving as the active sites for ORR/OER. The as‐prepared catalyst shows dramatically enhanced catalytic activity with half‐wave potential of 0.84 V (vs. RHE) for ORR and an overpotential of 0.36 V for OER in alkaline medium. More importantly, it exhibits excellent Zinc‐air battery charge/discharge cycling stability.

Introducing oxygen vacancies to transition-metal oxide materials would improve their catalytic activity but usually needs high-temperature or high-pressure conditions, and multi-step procedures, thus are not energy efficient and time consuming. Herein, laser ablation in liquid (LAL), a green, mild and effective approach is first employed to prepare CoOOH nanosheets with abundant oxygen vacancies and relatively thin thickness. Our theoretical and experimental results demonstrate that oxygen vacancies can facilitate the adsorption of water molecules and improve electrical conductivity, meanwhile, the relatively thin thickness can provide more active sites, thus leading to excellent OER activity of oxygen vacancy-modified CoOOH nanosheets. This work may provide a guide to explore other efficient non-noble metal catalysts for water oxidation.