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We design single-atom Cu anchored on Mo2C (Cu1/Mo2C) as an effective electrocatalyst towards electrochemical nitrite reduction to ammonia (NO2RR), exhibiting an NH3-faradaic efficiency of 91.5% with a corresponding NH3 yield rate of 472.9 μmol h−1 cm−2 at −0.6 V vs. RHE. Theoretical computations unravel that single-atomic Cu couples with the surface Mo atom of Mo2C to enable the construction of Cu–Mo dual-active centers, which can synergistically activate NO2− and minimize the NO2−-to-NH3 reaction energy barrier, whilst suppressing the competing hydrogen evolution reaction. [ABSTRACT FROM AUTHOR]

Single‐atom alloys hold great promise for electrocatalytic nitrogen reduction reaction (NRR), while the comprehensive experimental/theoretical investigations of SAAs for the NRR are still missing. Herein, PdFe1 single‐atom alloy metallene, in which the Fe single atoms are confined on a Pd metallene support, is first developed as an effective and robust NRR electrocatalyst, delivering exceptional NRR performance with an NH3 yield of 111.9 μg h−1 mg−1, a Faradaic efficiency of 37.8 % at −0.2 V (RHE), as well as a long‐term stability for 100 h electrolysis. In‐depth mechanistic investigations by theoretical computations and operando X‐ray absorption/Raman spectroscopy indentify Pd‐coordinated Fe single atoms as active centers to enable efficient N2 activation via N2‐to‐Fe σ‐donation, reduced protonation energy barriers, suppressed hydrogen evolution and excellent thermodynamic stability, thus accounting for the high activity, selectivity and stability of PdFe1 for the NRR. [ABSTRACT FROM AUTHOR]

ZrB2 is first explored as an earth-abundant metal diboride catalyst for highly efficient nitrogen reduction reaction (NRR). The synthesized ZrB2 nanocubes exhibited a highly attractive NRR performance with an NH3 yield of 37.7 μg h−1 mg−1 and a Faradaic efficiency 18.2% at −0.3 V (RHE). Theoretical calculations unraveled that active Zr centers enabled the effective activation of the N2 molecule via a unique tetranuclear side-on mode and concurrently impeded hydrogen evolution by restricting H+ adsorption. [ABSTRACT FROM AUTHOR]

The three-dimensional (3D) reduced graphene oxide/carbon nanotube nanocomposites (rGO/CNTs nanocomposites) and reduced graphene oxide nanocomposites (rGO nanocomposites) were anchored with amorphous MoS x , forming the MoS x -rGO/CNTs and MoS x -rGO nanocomposites. Their hydrogen evolution reaction (HER) activities were intensively evaluated. Results indicated that the rGO/CNTs nanocomposite provided more sites for the amorphous MoSx as compared with that of CNTs nanocomposite. Raman spectra of MoS x -rGO and MoS x -rGO/CNTs nanocomposites confirmed the amorphous state of MoS x in all MoS x anchored nanocomposites. TEM and SEM morphology indicated that the amorphous MoS x was well-dispersed on the rGO/CNTs and rGO nanocomposites. The amorphous MoS x nanoparticles in MoS x -rGO/CNTs and MoS x -rGO nanocomposites could provide more S atoms at their edges, and therefore greatly improve the HER activity. HER performances indicated that the rGO/CNTs and rGO nanocomposites anchored with crystalline MoS 2 exhibited poor HER performance. In contrast, MoS x -rGO/CNTs and MoS x -rGO nanocomposites anchored with a small amount of MoS x exhibited the excellent HER activity (179 mV of overpotential at 10 mA cm −2 ). Results also indicated that the HER activities of the MoS x -@rGO nanocomposites were a bit smaller than those of MoS x -rGO/CNTs nanocomposites. The CNTs in the rGO/CNTs nanocomposites would improve the intimate electrolyte/electrode contact and promote the high-rate charge transfer, which further strengthened their electrocatalytic hydrogen evolution performances. [ABSTRACT FROM AUTHOR]

In this work, a facile one-step hydrothermal method was developed to fabricate three types different of nanomaterials: the two-dimension (2D) of MoS 2 nanosheets; 3D spherical CuS nanoparticles; and 3D flower-like heterostructure of MoS 2 /CuS nanohybrid , respectively. The as-synthesized MoS 2 , CuS and MoS 2 /CuS were characterized by transmission electron microscopy (TEM), field emission scanning electron microscopy (SEM) and X-ray diffraction (XRD) etc. The morphology of the MoS 2 /CuS nanohybrid is different from the MoS 2 nanosheets and CuS nanoparticles. The hydrogen evolution reaction (HER) activity of MoS 2 nanosheets, CuS nanoparticles and MoS 2 /CuS nanohybrid, were investigated by the Linear Sweep Voltammetry (LSV) and Tafel slope. The HER activity of MoS 2 /CuS nanohybrid is better than those of MoS 2 nanosheets and CuS nanoparticles, which can be attributed to the good electron-transport ability of CuS and the strong reduction ability of hydrogen ions by MoS 2 . Thus, MoS 2 /CuS nanohybrid exhibited excellent activity for HER with a small onset potential of 0.15 V, a low Tafel slope of 63 mV dec −1 , and relatively good stability. However, the MoS 2 nanosheets and CuS nanoparticles respectively shows a bigger onset potential of 0.25 V and 0.35 V, a higher Tafel slope of 165 and 185 mV dec −1 . This 3D flower-like heterostructure of MoS 2 /CuS nanohybrid catalyst exhibits great potential for renewable energy applications. [ABSTRACT FROM AUTHOR]

Ag–Au core–shell triangular nanoprisms (Ag@Au TNPs) have aroused extensive research interest in the field of hydrogen evolution reaction (HER) due to their strong plasmon effect and stability. Here, Ag@Au TNPs were fabricated by the galvanic-free replacement method. Then, we loaded them on protonated g-C3N4 nanoprisms (P–CN) by the electrostatic self-assembly method as an efficient plasmonic photocatalyst for HER. The hydrogen production rate of Ag@Au TNPs/P–CN (4.52 mmol/g/h) is 4.1 times higher than that of P–CN (1.11 mmol/g/h) under simulated sunlight irradiation, making it the most competitive material for water splitting. The formed Schottky junction helps to trap the hot electrons generated from Ag@Au TNPs, and the well-preserved tips of the Ag@Au TNPs can effectively generate an electromagnetic field to inhibit the photogenerated electron–holes pairs recombination. This study suggests that the rational design of Ag@Au TNPs by the galvanic-free replacement method is an effective co-catalyst for HER and boosting the additional combination of plasmonic metals and catalyst metals for the enhancement to HER. [ABSTRACT FROM AUTHOR]