A ZnO@graphene composite exhibits enhanced performance for photocatalytic degradation and filtered removal of RhB dye, in comparison with ZnO and graphene, highlighting its potential applications for a variety of environmental issues.Scheme 1 An illustration of the synthesis of the ZGC.

Highly active, stable, and cheap Pt-free catalysts for the hydrogen evolution reaction (HER) are facing increasing demand as a result of their potential use in future energy-conversion systems. However, the development of HER electrocatalysts with Pt-like or even superior activity, in particular ones that can function under alkaline conditions, remains a significant challenge. Here, the synthesis of a novel carbon-loaded ruthenium nanoparticle electrocatalyst (Ru@CQDs) for the HER, using carbon quantum dots (CQDs), is reported. Electrochemical tests reveal that, even under extremely alkaline conditions (1 m KOH), the as-formed Ru@CQDs exhibits excellent catalytic behavior with an onset overpotential of 0 mV, a Tafel slope of 47 mV decade , and good durability. Most importantly, it only requires an overpotential of 10 mV to achieve the current density of 10 mA cm . Such catalytic characteristics are superior to the current commercial Pt/C and most noble metals, non-noble metals, and nonmetallic catalysts under basic conditions. These findings open a new field for the application of CQDs and add to the growing family of metal@CQDs with high HER performance.

This paper reports on the synthesis of Co(3)O(4)@graphene composites (CGC) and their applications as anode materials in lithium ion batteries (LIBs). Through a chemical deposition method, Co(3)O(4) nanoparticles (NPs) with sizes in the range of 10-30 nm were homogeneously dispersed onto graphene sheets. Due to their high electrical conductivity, the graphene sheets in the CGC improved the electrical conductivity and the structure stability of CGC. CGC displayed a superior performance in LIBs with a large reversible capacity value of 941 mA hg(-1) in the initial cycle with a large current density and an excellent cyclic performance of 740 mA hg(-1) after 60 cycles, corresponding to 88.3% of the theoretical value of CGC, owing to the interactions between graphene sheets and Co(3)O(4) NPs anchored on the graphene sheets. This synthesis approach may find its application in the design and synthesis of novel electrode materials used in LIBs.

In this paper, a Fe 3 O 4 nanocrystals@graphene composite (FGC) was synthesized via a chemical deposition method by using graphene oxide as a precursor. We also investigate the structures, physicochemical properties and applications of FGCs, involving superparamagnetic performance, and use as supercapacitors and lithium ion battery (LIBs). The results showed that the Fe 3 O 4 NCs were formed and incorporated onto the surface of the graphene sheets. The composite material FGC with a micrometre scale structure possessed similar size as the graphene sheets and exhibited superparamagnetic behavior at room temperature. The supercapacitance values of the FGC composites were enlarged compared with those of the graphene sheets or Fe 3 O 4 NCs, which is attributed to the interaction between the Fe 3 O 4 NCs and the graphene sheets. Meanwhile, a superior rechargeable stability of FGCs used as an anode material in LIBs can be observed.

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Piezochromic materials, which show color changes resulting from mechanical grinding or external pressure, can be used as mechanosensors, indicators of mechano-history, security papers, optoelectronic devices, and data storage systems. A class of piezochromic materials with unprecedented two-photon absorptive and yellow emissive carbon dots (CDs) was developed for the first time. Applied pressure from 0-22.84 GPa caused a noticeable color change in the luminescence of yellow emissive CDs, shifting from yellow (557 nm) to blue-green (491 nm). Moreover, first-principles calculations support transformation of the sp domains into sp -hybridized domains under high pressure. The structured CDs generated were captured by quenching the high-pressure phase to ambient conditions, thus greatly increasing the choice of materials available for a variety of applications.

A three dimensional composite was constructed by anchoring Fe(3)O(4) nanoparticles encapsulated within carbon shells onto reduced graphene oxide sheets, which exhibited enhanced anode performances in lithium ion batteries with a specific capacity of 842.7 mAh g(-1) and superior recycle stability after 100 cycles.

Fullerene can activate molecular hydrogen and is a novel nonmetal hydrogenation catalyst. The hydrogenation of aromatic nitro compounds to amino aromatics is achieved on this catalyst with high conversion and selectivity under 1 atmospheric pressure of H(2) and light irradiation at room temperature or under conditions of 120-160 degrees C and 4-5 MPa H(2) pressure without light irradiation, which is comparable to the case with a noble metal catalyst.