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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.

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The Cu 2 O/reduced graphene oxide (Cu 2 O/rGO) composites with effective crystallographic facet controlling of Cu 2 O crystals were fabricated through a simple one-step wet chemistry method. The crystallographic facet-dependent photocatalytic performance of Cu 2 O was confirmed, favoring the cuboctahedral Cu 2 O with f100g and f111g facets and a better photocatalytic activity when compared to cubic and octahedral ones. This was attributed to the slight difference of surface energy between f100g and f111g facets which served as a driving force to promote the separation of photogenerated electron-hole pairs. Moreover, the introduction of two-dimensional rGO sheets could accelerate the transfer of photogenerated electrons from Cu 2 O to rGO, which further promoted the separation of photogenerated electron-hole pairs and the degradation of methyl orange (MO) under visible-light irradiation. The cuboctahedral Cu 2 O/rGO composite exhibited a superb photocatalytic performance with the degradation percentage of MO about 97.6% after one periodic photocatalysis due to the synergistic effect of cuboctahedral Cu 2 O and rGO sheets, foreboding its potential application as photocatalyst.Keywords: Cu 2 O/rGO composite; crystallographic facet control; photocatalytic activity; synergistic effect.With the increasing problem of environmental pollution, particularly serious drinking water safety induced by organic contaminations has become the focus of attention. Photocatalytic degradation of organic dyes under visible-light irradiation through effective, cheap and stable catalysts is a good strategy. 1-4 Semiconductor-based nanocomposites with unique physical and chemical properties are regarded as ideal candidates and photocatalysts to solve the above problems. Among these, Cu 2 O as an intrinsic p-type semiconductor (band gap of 2.2 eV) can effectively absorb and utilize solar spectrum in the visible-light region. 5,6 Additionally, low-cost and easy-to-prepare Cu 2 O crystals with different exposed crystallographic facets show many controllable optical, electrical and catalytic properties, indicating their preponderance as photocatalysts. 7 However, many factors limit the photocatalytic efficiency of Cu 2 O crystals including the slow electron transfer, rapid electron-hole recombination, and poor photochemical stability. 2,3,7 In order to overcome these deficiencies, many attempts have been carried out to extend the wavelength range of photoresponse, increase lightharvesting and charge-separating efficiency at the material interface, and improve the photochemical stability by constructing Cu 2 O-semiconductor (Cu 2 O/TiO 2 5 and Cu 2 O/ZnO 8 ) heterojunctions, or introducing high-conductive materials (noble metal 9 and graphene 10-12 ). Until now, the research on structural, optical and photocatalytic tunability of Cu 2 Obased photocatalysts is still limited and critically important since photocatalytic activity is sensitively dependent upon synergistic properties of components in composites.In this paper, we fabricated Cu 2 O/...

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