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Rational design and preparation of single‐atom catalysts provide a promising strategy to significantly improve the electrocatalytic activity for water splitting. In particular, single atoms anchored at cationic vacancies can enhance the stability of the catalysts and improve reaction kinetics. In this work, Pt single atoms are loaded at layered α‐Ni2/3Fe1/3(OH)2 by oxidizing Fe2+ with H2PtCl6, and specifically, Pt atoms are anchored at in situ generated iron cationic vacancies during the process, resulting in stabilized Pt single atoms in the surface of α‐Ni2/3Fe1/3(OH)2 with the maximum loading of ≈6.15 wt%. The Pt single atoms not only act as active sites for hydrogen evolution reaction but also regulate the electronic structure of NiFe hydroxides and activate Ni atoms adjacent to Pt for oxygen evolution reaction. Therefore, the water‐splitting electrolyzer assembled with such a bifunctional catalyst shows a smaller overpotential than that with RuO2 and 20 wt% Pt/C catalysts as the anode and cathode, respectively, and efficient solar‐to‐hydrogen conversion. The results demonstrate the practical application of single‐atom Pt catalysts with low cost, large loading, and facile preparation route. [ABSTRACT FROM AUTHOR]

Promoting the solution phase formation of Li2O2 rather than on the cathode surface is a key issue for high‐performance Li–O2 batteries. Protic additives have been reported to guide the discharge of Li2O2 in the electrolyte solution, while further advances are stalled by the intrinsical reactivity to Li metal to deteriorate the lifespan of Li–O2 batteries. Herein, rhodamine B (RhB), a protic additive, is first introduced into electrolyte as a phase‐transfer catalyst to achieve solution phase formation of Li2O2. The yield of Li2O2 is 90.79%, and the discharge capacity is 46 000 mAh gcarbon−1 at current density of 1000 mA gcarbon−1, which is 23‐fold higher than that of blank electrolyte. Density functional theory calculations further demonstrate the feasibility of RhB to boost solution phase discharge. Most notably, the free chlorine ion in RhB assists the in situ formation of a stable Li+‐conducting solid electrolyte interphase to protect Li anode from corrosion and dendrite formation during cycling. As a result, Li||Li symmetric cells exhibit a long cycle performance up to 1300 h at 1 mA cm−2 with low hysteresis voltage. Benefiting from the above results, Li–O2 batteries with RhB present long cycle stability. [ABSTRACT FROM AUTHOR]