A controllable vacuum-diffusion method for gradual phosphidation of carbon coated metallic Co nanoparticles into Co/CoP Janus nanoparticles is reported. Janus Co/CoP nanoparticles, as typical Mott-Schottky electrocatalysts, exhibit excellent hydrogen evolution reaction and oxygen evolution reaction performance in various electrolytes across wide pH range along with high durability. The Mott-Schottky Co/CoP catalyst can work as bifunctional electrode materials for overall water splitting in wide pH range and can achieve a current density of 10 mA cm −2 in neutral electrolyte at only 1.51 V.

The traditional NH3 production method (Haber–Bosch process) is currently complemented by electrochemical synthesis at ambient conditions, but the rather low selectivity (as indicated by the Faradaic efficiency) for the electrochemical reduction of molecular N2 into NH3 impedes the progress. Here, we present a powerful method to significantly boost the Faradaic efficiency of Au electrocatalysts to 67.8% for the nitrogen reduction reaction (NRR) by increasing their electron density through the construction of inorganic donor–acceptor couples of Ni and Au nanoparticles. The unique role of the electron-rich Au centers in facilitating the fixation and activation of N2 was also investigated via theoretical simulation methods and then confirmed by experimental results. The highly coupled Au and Ni nanoparticles supported on nitrogen-doped carbon are stable for reuse and long-term performance of the NRR, making the electrochemical process more sustainable for practical application.

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Production of ammonia is currently realized by the Haber–Bosch process, while electrochemical N2 fixation under ambient conditions is recognized as a promising green substitution in the near future. A lack of efficient electrocatalysts remains the primary hurdle for the initiation of potential electrocatalytic synthesis of ammonia. For cheaper metals, such as copper, limited progress has been made to date. In this work, we boost the N2 reduction reaction catalytic activity of Cu nanoparticles, which originally exhibited negligible N2 reduction reaction activity, via a local electron depletion effect. The electron-deficient Cu nanoparticles are brought in a Schottky rectifying contact with a polyimide support which retards the hydrogen evolution reaction process in basic electrolytes and facilitates the electrochemical N2 reduction reaction process under ambient aqueous conditions. This strategy of inducing electron deficiency provides new insight into the rational design of inexpensive N2 reduction reaction catalysts with high selectivity and activity.

Highly efficient fixation of CO 2 for the synthesis of useful organic carbonates has drawn much attention. The design of sustainable Lewis acid−base pairs, which has mainly relied on expensive organic ligands, is the key challenge in the activation of the substrate and CO 2 molecule. Here, we report the application of Mott−Schottky type nanohybrids composed of electron-deficient Cu and electron-rich N-doped carbon for CO 2 fixation. A ligand-free and additive-free method was used to boost the basicity of the carbon supports and the acidity of Cu by increasing the Schottky barrier at their boundary, mimicking the beneficial function of organic ligands acting as the Lewis acid and base in metal−organic frameworks (MOFs) or polymers and simultaneously avoiding the possible deactivation associated with the necessary stability of a heterogeneous catalyst. The optimal Cu/NC-0.5 catalyst exhibited a remarkably high turnover frequency (TOF) value of 615 h −1 at 80 °C, which is 10 times higher than that of the state-of-the-art metal-based heterogeneous catalysts in the literature.E xcessive emission of carbon dioxide has triggered numerous environmental problems. 1−3 Efficient reuse of CO 2 , which is an inexpensive, abundant, and nontoxic gas, is consistently considered a promising green chemistry process. 1−5 However, the high chemical stability of CO 2 makes its conversion difficult. 6 Current strategies for chemical fixation of CO 2 mainly focus on the conversion of CO 2 into useful organic carbonates, carbamates, ureas, and carboxylic acids. 7 Cycloaddition of CO 2 to epoxides is an important method for the synthesis of cyclic carbonates, 8,9 which are of great interest in industry as lithium battery electrolytes, nonprotic polar solvents, and monomers used for generating polycarbonates. 10 Recently, metal−organic frameworks (MOFs) 11,12 and porous ionic polymers 13 have been developed as reusable heterogeneous catalysts for the coupling reaction. This pioneering work has clearly demonstrated the importance of Lewis acid and/or base groups in facilitating the fixation of CO 2 and the activation of epoxides, 14−16 even though the expensive and complex method for the synthesis of MOF materials will limit their practical applications. In principle, electron-rich and electron-deficient areas at the boundary of a