Single-atom electrocatalysts (SACs) toward hydrogen evolution reaction (HER) have been extensively studied owing to their high mass activity and atom utilization. Although platinum (Pt) based SACs have been reported frequently, optimizing the metal-support interaction to achieve low valence state Pt species is still a challenge. Here, the carbon supported α-MoC 1−x nanoparticles are used to anchor zero-valent Pt single atoms (Pt SA /α-MoC 1−x @C) as electrocatalyst for pH-universal HER. The Pt SA /α-MoC 1−x @C with optimized Pt loading of 0.75 wt% shows a low overpotential (21, 12, and 36 mV at 10 mA cm -2 ) and high turnover frequencies (27.00, 31.98, and 21.39 H 2 s -1 at 100 mV) for HER under alkaline, acidic, and neutral electrolyte conditions. Experimental evidence combing density functional theory calculations confirm that the charge polarization leads to a zero-valence state of Pt single atom and further optimized the adsorption/desorption energy of intermediates, further accelerating the reaction dynamics for HER.

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Excellent corrosion resistance is crucial for photovoltaic devices to acquire high and stable performance under high corrosive complicated environments. Creative inspiration comes from sandwich construction, whereby Fe3O4 nanoparticles were anchored onto hollow core-shell carbon mesoporous microspheres and wrapped by N-graphene nanosheets (HCCMS/Fe3O4@N-RGO) to obtain integrated high corrosive resistance and stability. The as-prepared multiple composite material possesses outstanding performance as a result of structure optimization, performance improvement, and interface synergy. Therefore, it can effectively suppress corrosion from the electrolyte in recycled tests many times, indicating the ultrahigh corrosion resistance life of this double carbon-based nanocomposite. Furthermore, the electrical conductivity and conversion efficiency of the composite are well maintained due to the triple synergistic interactions, which could serve as a guideline in establishing high-performance multifunctional HCCMS/Fe3O4@N-RGO with great prospects in energy devices, such as lithium batteries, supercapacitors and electrode materials, etc.

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The porous structure and excellent specific surface area are superior for use as a counter electrode (CE) material. In addition, N-doped graphene possesses a remarkable electron-transfer pathway and many active sites. Therefore, a novel idea is to wrap uniform flower-like mesoporous FeO (FeOUFM) in an N-doped graphene (N-RGO) network structure to enhance the power conversion efficiency (PCE). The hybrid materials of FeOUFM@N-RGO are first used as a CE in dye-sensitized solar cells (DSSCs), showing a preeminent conductive interconnected 3D porous structure with more catalytic activity sites and a better ability for and a faster reaction rate of charge transfer, resulting in quicker reduction of I than Pt. A 9.26% photoelectric conversion efficiency has been achieved for the DSSCs with FeOUFM@N-RGO as the CE, which is beyond the value of Pt (7.72%). The positive synergetic effect between FeO and N-RGO is mainly responsible for the remarkable photoelectric property enhancement of this uniform flower-like mesoporous FeO wrapped in N-doped graphene networks, as demonstrated by the Tafel polarization, electrochemical impedance spectra, and CV curves. These methods will provide a simple way to effectively reproduce CE materials.