Heterogeneous catalysts of inexpensive and reusable transition-metal are attractive alternatives to homogeneous catalysts; the relatively low activity of transition-metal nanoparticles has become the main hurdle for their practical applications. Here, the de novo design of a Mott–Schottky-type heterogeneous catalyst is reported to boost the activity of a transition-metal nanocatalyst through electron transfer at the metal/nitrogen-doped carbon interface. The Mott–Schottky catalyst of nitrogen-rich carbon-coated cobalt nanoparticles (Co@NC) was prepared through direct polycondensation of simple organic molecules and inorganic metal salts in the presence of g-C3N4 powder. The Co@NC with controllable nitrogen content and thus tunable Fermi energy and catalytic activity exhibited a high turnover frequency (TOF) value (8.12 mol methyl benzoate mol–1 Co h–1) for the direct, base-free, aerobic oxidation of benzyl alcohols to methyl benzoate; this TOF is 30-fold higher than those of the state-of-the-art transition-metal-based nanocatalysts reported in the literature. The presented efficient Mott–Schottky catalyst can trigger the synthesis of a series of alkyl esters and even diesters in high yields.

Synthesizing cost-efficient and robust bifunctional electrocatalysts for both neutral and alkaline water splitting is highly desired, but still remains a great challenge due to the sluggish hydrogen/oxygen evolution reaction (HER/OER) kinetics. Currently, noble Pt, Ru, and Ir-based catalysts are the most efficient ones, but their high cost and scarcity greatly restrict their broad applications. [2] Therefore, enormous efforts have been made toward developing suitable and cheaper catalysts with earthabundant materials for commercial applications. In the past years, a large number of non-noble-metal based catalysts, including transition metal phosphides, nitrides, carbides, and oxides, had good development prospects in catalytic fields. [3] Among these, transition metal phosphides (TMPs) such as Fe x P, Co x P, and Ni x P are promising and considered as the most probable alternatives to the noblemetal based catalysts due to their abundant reserves, high stability, non-toxicity, fast charge transfer, and electrical conductivity. [4] However, many studies demonstrated that TMPs exhibited excellent hydrogen evolution reaction (HER) activity (it may be attributed to the reported hydrogenase-like catalytic mechanism), [5] but poor oxygen evolution reaction (OER) activity. So, it is an urgent to improve their catalytic behavior. There are two effective strategies to solve the above problems:Constructing cost-efficient and robust bifunctional electrocatalysts for both neutral and alkaline water splitting is highly desired, but still affords a great challenge, due to sluggish hydrogen/oxygen evolution reaction (HER/OER) kinetics. Herein, an in situ integration engineering strategy of oxygen-vacancy and core-shell heterojunction to fabricate an anemone-like CoP@CoOOH core-shell heterojunction with rich oxygen-vacancies supported on carbon paper (CoP@CoOOH/CP), is described. Benefiting from the synergy of CoP core and oxygen-vacancy-rich CoOOH shell, the as-obtained CoP@CoOOH/CP catalyst displays low overpotentials at 10 mA cm -2 for HER (89.6 mV/81.7 mV) and OER (318 mV/200 mV) in neutral and alkaline media, respectively. Notably, a two-electrode electrolyzer, using CoP@CoOOH/CP as bifunctional catalyst to achieve 10 mA cm -2 , only needs low-cell voltages in neutral (1.65 V) and alkaline (1.52 V) electrolyte. Besides, systematically experimental and theoretical results reveal that the core-shell heterojunction efficiently accelerates the catalytic kinetics and strengthens the structural stability, while rich oxygen-vacancies efficiently decrease the kinetic barrier and activation energy, and reduce the energy barrier of the rate-determiningstep for OER intermediates, thus intrinsically boosting OER performance. This work clearly demonstrates that oxygen-vacancy and core-shell heterojunction engineering provide an effective strategy to design highly-efficient non-precious, bi-functional electrocatalysts for pH-universal water splitting.The ORCID identification number(s) for the author(s) of this article can be found under h...

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