Chemical doping has been demonstrated to be an effective way to realize new functions of graphene as metal-free catalyst in energy-related electrochemical reactions. Although efficient catalysis for the oxygen reduction reaction (ORR) has been achieved with doped graphene, its performance in the hydrogen evolution reaction (HER) is rather poor. In this study we report that nitrogen and sulfur co-doping leads to high catalytic activity of nanoporous graphene in HER at low operating potential, comparable to the best Pt-free HER catalyst, 2D MoS2 . The interplay between the chemical dopants and geometric lattice defects of the nanoporous graphene plays the fundamental role in the superior HER catalysis.

Single-atom nickel dopants anchored to three-dimensional nanoporous graphene can be used as catalysts of the hydrogen evolution reaction (HER) in acidic solutions. In contrast to conventional nickel-based catalysts and graphene, this material shows superior HER catalysis with a low overpotential of approximately 50 mV and a Tafel slope of 45 mV dec(-1) in 0.5 M H2SO4 solution, together with excellent cycling stability. Experimental and theoretical investigations suggest that the unusual catalytic performance of this catalyst is due to sp-d orbital charge transfer between the Ni dopants and the surrounding carbon atoms. The resultant local structure with empty C-Ni hybrid orbitals is catalytically active and electrochemically stable.

The "edge-free" monolayer MoS2 films supported by 3D nanoporous gold show high catalytic activities towards hydrogen evolution reaction (HER), originating from large out-of-plane strains that are geometrically required to manage the 3D curvature of bicontinuous nanoporosity. The large lattice bending leads to local semiconductor-to-metal transition of 2H MoS2 and the formation of catalytically active sites for HER.

Chemical doping has been demonstrated to be an effective way to realize new functions of graphene as metal‐free catalyst in energy‐related electrochemical reactions. Although efficient catalysis for the oxygen reduction reaction (ORR) has been achieved with doped graphene, its performance in the hydrogen evolution reaction (HER) is rather poor. In this study we report that nitrogen and sulfur co‐doping leads to high catalytic activity of nanoporous graphene in HER at low operating potential, comparable to the best Pt‐free HER catalyst, 2D MoS2. The interplay between the chemical dopants and geometric lattice defects of the nanoporous graphene plays the fundamental role in the superior HER catalysis.

Single-atom nickel dopants anchored to threedimensional nanoporous graphene can be used as catalysts of the hydrogen evolution reaction (HER) in acidic solutions.In contrast to conventional nickel-basedc atalysts and graphene, this material shows superior HER catalysis with al ow overpotential of approximately 50 mV and aT afel slope of 45 mV dec À1 in 0.5 m H 2 SO 4 solution, together with excellent cycling stability.E xperimental and theoretical investigations suggest that the unusual catalytic performance of this catalyst is due to sp-d orbital charge transfer between the Ni dopants and the surrounding carbon atoms.T he resultant local structure with empty C-Ni hybrid orbitals is catalytically active and electrochemically stable.

The combinations of hollow MoS 2 micro@nano-spheres were successfully fabricated through a one-step hydrothermal method. A possible growth mechanism was presented in detail based on time-dependent experimental facts. Besides, the photocatalytic activities of the samples were evaluated by monitoring the photodegradation of methylene blue (MB). The adsorption value of 150 mg g À1 shows a strong adsorption capability in the dark. After irradiation for only 30 min, the remaining MB in solution is about 9.7%. Moreover, the humidity sensing properties of the samples were measured for the first time. The results revealed high sensitivity at high RH, small humidity hysteresis, fast response and recovery times, and good stability. The greatest sensitivity is 32.19 nF/% RH and the maximum hysteresis is $6.3% RH.For humidity cycling of 17.2-89.5-17.2% RH, the response and recovery times are $140 s and $80 s, respectively. Capacitance fluctuations for one month are less than AE7% at various relative humidities (RHs).

A novel hierarchical MoS2@SnO2 hetero-nanoflower was successfully synthesized by a facile, two-step hydrothermal method without using any additives or surfactants. One possible growth mechanism of the hetero-nanostructure was presented in detail based on OH(-) ion-dependent experimental facts. Due to the formation of the p-n junctions and the increased specific surface area in the composites, an outstanding photocatalytic activity of the as-prepared sample was obtained by monitoring the photodegradation of methylene blue (MB). According to the data, after irradiation for 100 min, the remaining MB in solution is about 26% for MoS2 nanoflowers and 9.5% for MoS2@SnO2 hetero-nanoflowers. Moreover, an excellent field-emission performance was obtained from MoS2@SnO2 hetero-nanoflower relative to the pure MoS2 with the turn-on field decreasing from 4.2 V μm(-1) to 3.4 V μm(-1) and the threshold field decreasing from 6.2 V μm(-1) to 5.2 V μm(-1), which is mainly attributed to the increased field-emission points and MoS2-SnO2 heterojunction.

Developing highly active electrocatalysts with low costs and long durability for oxygen evolution reactions (OER) is crucial towards the practical implementations of electrocatalytic water-splitting and rechargeable metal-air batteries. Anodized nanostructured...