Under the double pressure of both the energy crisis and environmental pollution, the exploitation and utilization of hydrogen, a clean and renewable power resource, has become an important trend in the development of sustainable energy-production and energy-consumption systems. In this regard, the electrocatalytic hydrogen evolution reaction (HER) provides an efficient and clean pathway for the mass production of hydrogen fuel and has motivated the design and construction of highly active HER electrocatalysts of an acceptable cost. In particular, graphene-based electrocatalysts commonly exhibit an enhanced HER performance owing to their distinctive structural merits, including a large surface area, high electrical conductivity, and good chemical stability. Considering the rapidly growing research enthusiasm for this topic over the last several years, herein, a panoramic review of recent advances in graphene-based electrocatalysts is presented, covering various advanced synthetic strategies, microstructural characterizations, and the applications of such materials in HER electrocatalysis. Lastly, future perspectives on the challenges and opportunities awaiting this emerging field are proposed and discussed.

The design and construction of high-performance platinum-based electrode catalysts with acceptable cost are the keys to advances in the field of direct methanol fuel cells (DMFCs). Herein, we report an efficient bottom-up approach for the large-scale production of ultrafine Pt NP-decorated 3D hybrid architectures by employing graphene (RGO) and MXene (Ti 3 C 2 T x ) nanosheets as cobuilding blocks. Benefiting from their distinct structural merits, such as highly interconnected porous carbon networks, large specific surface areas, homogeneous metallic Pt dispersion, and good electron conductivity, the resulting 3D Pt/RGO−Ti 3 C 2 T x architectures express surprisingly high catalytic activity, reliable long-term stability, and strong poison tolerance as they are utilized as anode DMFC catalysts, which are more competitive than those for conventional Pt catalysts supported by carbon black, carbon nanotube, RGO, and Ti 3 C 2 T x materials. Density functional theory calculation further reveals an optimized band structure of the RGO− Ti 3 C 2 T x support as well as its strong electronic interactions with Pt NPs, which are essential for the exceptional electrocatalytic properties toward methanol oxidation reaction.

Viruses have drawn much attention in recent years due to increased recognition of their important roles in virology, immunology, clinical diagnosis, and therapy. Because the biological and physical properties of viruses significantly impact their applications, quantitative detection of individual virus particles has become a critical issue. However, due to various inherent limitations of conventional enumeration techniques such as infectious titer assays, immunological assays, and electron microscopic observation, this issue remains challenging. Thanks to significant advances in nanotechnology, nanostructure-based electrical sensors have emerged as promising platforms for real-time, sensitive detection of numerous bioanalytes. In this paper, we review recent progress in nanopore-based electrical sensing, with particular emphasis on the application of this technique to the quantification of virus particles. Our aim is to provide insights into this novel nanosensor technology, and highlight its ability to enhance current understanding of a variety of viruses.

Direct methanol fuel cells with high energy conversion efficiency and low hazard emissions have aroused great attention from both academic and industrial communities, but their large-scale commercial application has been blocked by high costs as well as short lifespan of the anode Pt catalysts. Here, we demonstrate a simple and scalable noncovalent strategy for the synthesis of quasi-one-dimensional (1D) Pt nanoworms grown on poly­(diallyldimethyl-ammonium chloride) (PDDA)-functionalized Ti3C2T x nanosheets as anode catalysts for methanol electrooxidation. Interestingly, the introduction of PDDA on Ti3C2T x nanosheets can not only effectively adjust their surface charge property to strengthen the electrostatic interaction between metal and support but also induce the stereoassembly of worm-shaped Pt nanocrystals with abundant catalytically active grain boundaries, which enable the resulting hybrid to express high electrocatalytic activity, remarkable durability, and strong antipoisoning ability for methanol electrooxidation, which are better than those of the traditional Pt nanoparticle electrocatalysts loaded on carbon black, carbon nanotubes, reduced graphene oxide, and MXene matrixes. Theoretical simulations disclose that the more stable worm-shaped Pt configuration with an optimized electronic structure on the Ti3C2T x surface possesses a weaker CO adsorption ability than that of the Pt nanoclusters, thereby providing a dramatically enhanced and sustainable electrocatalytic performance.

Direct methanol fuel cell (DMFC) has been considered as an ideal “green” energy converter because of its high energy-conversion efficiency and low pollution emissions, while the high costs and poor...

A self-assembly approach is developed for the synthesis of highly-active Pt on 3D low-defect CNT/N-doped graphene aerogels.

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Nanocrystalline cellulose (NCC) is a kind of natural biopolymers with merits of large surface area, high specific strength and unique optical properties. This report shows that NCC can serve as the substrate, allowing glucose to reduce Tollen's reagent to produce silver nanoparticles (AgNPs) at room temperature. The generation of AgNPs is affected by the factors such as the concentrations of silver ions, NCC and glucose, as well as the different reaction temperatures. The AgNPs with NCC are applied for the development of a visual, quantitative, nonenzymatic and high-sensitive assay for glucose detection in serum. This assay is also used for monitoring the concentration change of glucose in medium during cell culture. For the antibacterial activity, the minimal inhibitory concentration (MIC) of the generated AgNPs with NCC is much lower than that of commercial AgNPs, attributed to the good dispersion of AgNPs with the presence of NCC. As NCC exhibits unique advantages including green, stable, inexpensive, and abundant, the NCC-based generation of AgNPs may find promising applications in clinical diagnosis, environmental monitoring, and the control of bacteria.