Anthracite is a plentiful and affordable natural resource with a high coalification degree and many graphene-like sp2 carbon crystallites, which is fascinating for the development of novel coal-based carbon materials to achieve the value-added utilization of coal resources. In this work, a facile one-step ultrasonic physical tailoring procedure for the fabrication of blue luminescent coal-derived graphene quantum dots (C-GQDs) was exploited using Taixi Anthracite as the carbon source. The as-prepared C-GQDs possess uniformly distributed sizes and diameters of 3.2 ± 1.0 nm, and their aqueous solution can remain in stable homogeneous phase even after 2 months at room temperature. Moreover, we found that the C-GQDs exhibit two different distinctive emission modes. The evolution of the surface states and the electronic structure analysis revealed that two different types of fluorescence centers could be ascribed to nanosized sp2 carbon domains and oxygen functional group defects. Meanwhile, unique electronic and chemical properties endow the C-GQDs with a sensitive response to Cu2+. C-GQDs were demonstrated as potential fluorescent materials for reliable, label-free, and selective detection of Cu2+, showing great promise in real-world sensor applications.

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It is demonstrated that the low-dimensional Fe-doped SnO2 flower-like spheres with enhanced breathing sensing property are synthesized by a simple template- and surfactant-free hydrothermal method.

Graphene as a suitable electrode has been extensively used for electrochemical double‐layer capacitors based on its excellent properties, including high electrical conductivity and large specific surface area. However, one of the drawbacks is the unavoidable stacking tendency between the graphene nanosheets, resulting in limited electrochemically specific surface area. Herein, novel graphene nanosheets supported by hollow nitrogen‐doped carbon frameworks derived from ZIF‐8 (GPNC) were fabricated through a simple polyethyleneimine (PEI)‐assisted pyrolysis strategy, to boost capacitance performance. Benefiting from the unique scaffold/support role of hollow nitrogen‐doped carbon frameworks within the graphene interlayer, the GPNC with a large specific surface area, along with ample micropore/mesopore channels and high nitrogen content, is capable of facilitating electron and electrolyte ion migration kinetics and enhancing intrinsic electrochemical activity. Thus, the GPNC exhibits the highest charge storage of 218 F g−1 and superior rate capability of 74 % when the current density increased from 0.5 to 20 Ag−1 in comparison to pristine graphene and common ZIF‐derived carbon/graphene electrodes. The assembled GPNC//GPNC two‐electrode system further delivers a maximum power of 9080 Wkg−1 with outstanding electrochemical retention of 84 % over 10 000 cycles.

Herein, a facile in situ self-assembly strategy is developed to fabricate two-dimensional nanospherical Fe3O4@nitrogen-doped graphene nanosheet (Fe3O4@NGNS) composite using Fe-based zeolitic imidazolate frameworks (Fe-ZIFs) and graphene oxide (GO) as the precursors. This in situ synthesis tactic can availably suppress both the agglomeration and the huge volume change of nanospherical Fe3O4. As an anode of lithium ion batteries, Fe3O4@NGNS exhibits preeminent cycle stability and rate performance, which inhabits a stable specific capacity of 502.3 mAh g–1 at the current density of 2 A g–1 after 200 cycles. Moreover, the electrode material easily recovered a large capacity of 1045.82 mAh g–1, after the current density returned to 0.1 A g–1, showing excellent reversibility. The enhanced electrochemical performance is attributed to the 2D architecture formed by the nanospherical Fe3O4 and graphene nanosheet, which offer additional space for the storage of electrolytes, thereby shorting the path of ion insertion/deinsertion. This renders Fe3O4@NGNS a promising high-performance anode candidate for lithium ion batteries.

To achieve a good electrochemical performance of lithium-ion batteries (LIBs), the design and optimization of the anode is a key issue. Herein, the fabrication of nitrogen-doped porous graphene hybrid nanosheets (denoted as N-PGNS) is proposed via a simple functional group-induced growth of zeolitic imidazolate framework (ZIF-8) on graphene oxides (GO) followed by a one-step pyrolysis strategy. Detailed characterizations reveal that the N-doped porous carbon derived from ZIF-8 is homogeneously anchored on graphene, and can provide high electroactivity and numerous diffusion channels for fast Li+ transport. Meanwhile, the incorporation of graphene as a conductive framework and supporting substrate can accelerate the transfer of electrons. Taking advantage of the synergistic role between the graphene framework and N-doped porous carbon, the N-PGNS exhibits a stable reversible specific capacity of 741.8 mA h g–1 as the anode for LIBs, which is notably higher than that of the N-doped porous carbon obtained directly by pyrolysis of ZIF-8. Furthermore, the N-PGNS electrodes also show superior electrochemical stability with an initial capacity of 90.38% over 1000 cycles at 5 A g–1. The current strategy, which can control and adjust the growth of ZIF-8 via the inducing effect of GO, provides a promising solution to construct graphene hybrid nanosheets for high-performance LIBs.