a b s t r a c tThree-dimensional (3D) porous molybdenum disulfide/nitrogen-doped reduced graphene oxide (MoS 2 / N-rGO) hydrogels were fabricated through a facile and controllable one-pot hydrothermal method. The nanosized MoS 2 ultrathin nanosheets were uniformly and vertically dispersed on the rGO framework after nitrogen incorporation. The incorporated nitrogen in rGO played a key role for nano-scaling of MoS 2 due to the protonation at pyridinic N-doping sites on carbon surface. The vertically aligned edge of nanosized MoS 2 sheets, nitrogen incorporation of rGO and 3D network structure made the MoS 2 /N-rGO highly efficient for hydrogen evolution reaction, with improved double-layer capacitance and turnover frequency, small onset overpotential of 119 mV, low Tafel slope of 36 mV$decade À1 and superior longtime catalytic stability.

Manganese dioxide nanowires (MnO2 NWs) anchored on carbon fiber cloth (CFC) were fabricated through a simple hydrothermal reaction and used as integrated electrodes for supercapacitor. The morphology-dependent electrochemical performance of MnO2 NWs was confirmed, yielding good capacitance performance with a high specific capacitance of 3.88[Formula: see text][Formula: see text] at a charge–discharge current density of 5[Formula: see text][Formula: see text] and excellent stability of 91.5% capacitance retention after 3000 cycles. Moreover, the composite electrodes were used to fabricate supercapacitors, which showed a high specific capacitance of 194[Formula: see text][Formula: see text] at a charge–discharge current density of 2[Formula: see text][Formula: see text] and high energy density of 0.108[Formula: see text][Formula: see text] at power density of 2[Formula: see text][Formula: see text], foreboding its potential application for high-performance supercapacitor.

A NiCo2O4/MnO2 heterostructure with high mass loading MnO2 microflowers was built on the surface of 3D graphene/nickel foam for the preparation of an asymmetric supercapacitor with splended energy density (45.9 Wh kg−1).