Guangxun Zhang

Transition metal oxides with one-dimensional/one-dimensional-analogue nanostructures for advanced supercapacitors

With the increasing energy demand and the overconsumption of fossil fuels, renewable energy-storage devices with higher efficiency are of great interest. In particular, supercapacitors have recently gained significant attention due to their excellent charge–discharge performance, long-term cycle lifetimes, and high specific power. In addition, supercapacitors could also make up the difference in energy and power between batteries and traditional capacitors. In the future, the promising family of transition metal oxides (TMOs) will play a significant role in environmentally friendly, low-cost, and high-powered energy storage. Furthermore, one-dimensional (1D) and one-dimensional-analogue nanostructures could remarkably enhance the characteristic properties of TMOs. In this review, we focused on the recent progress in the preparation and electrochemical properties of the next-generation supercapacitors.

Facile synthesis of ultrathin Ni-MOF nanobelts for high-efficiency determination of glucose in human serum

Ultrathin Ni-MOF nanobelts, [Ni20(C5H6O4)20(H2O)8]·40H2O(Ni-MIL-77 NBs), were synthesized by a facile one-pot solution process and can be used as an efficient catalyst electrode for glucose oxidation under alkaline conditions. Electrochemical measurements demonstrate that the NB/GCE, when used as a non-enzymatic glucose sensor, offers superior analytical performances with a wide linear range (from 1 μM to 500 μM), a low detection limit (0.25 μM, signal-to-noise = 3), and a response sensitivity of 1.542 μA mM-1 cm-2. Moreover, it can also be applied for glucose detection in human blood serum with the relative standard deviation (RSD) of 7.41%, showing the high precision of the sensor in measuring real samples.

Synthetic methods and electrochemical applications for transition metal phosphide nanomaterials

Currently, the great demand for energy has triggered the exploration of new devices for energy storage and conversion. For these devices, electrode materials with excellent performance are strongly needed. In particular, transition metal phosphide nanomaterials are emerging with excellent performances. Transition metal phosphide nanomaterials have been utilized in Li-ion batteries, Na-ion batteries, supercapacitors, solar cells, electrocatalysis, etc. This review summarizes recent developments and challenges in transition metal phosphide nanomaterials, with a focus on synthetic methods and electrochemical applications.

Ultrathin Nanosheet Assembled Sn0.91Co0.19S2 Nanocages with Exposed (100) Facets for High-Performance Lithium-Ion Batteries

Ultrathin 2D inorganic nanomaterials are good candidates for lithium-ion batteries, as well as the micro/nanocage structures with unique and tunable morphologies. Meanwhile, as a cost-effective method, chemical doping plays a vital role in manipulating physical and chemical properties of metal oxides and sulfides. Thus, the design of ultrathin, hollow, and chemical doped metal sulfides shows great promise for the application of Li-ion batteries by shortening the diffusion pathway of Li ions as well as minimizing the electrode volume change. Herein, ultrathin nanosheet assembled Sn0.91 Co0.19 S2 nanocages with exposed (100) facets are first synthesized. The as-prepared electrode delivers an excellent discharge capacity of 809 mA h g-1 at a current density of 100 mA g-1 with a 91% retention after 60 discharge-charge cycles. The electrochemical performance reveals that the Li-ion batteries prepared by Sn0.91 Co0.19 S2 nanocages have high capacity and great cycling stability.

Ultrathin Cu-MOF@δ-MnO2 nanosheets for aqueous electrolyte-based high-voltage electrochemical capacitors

With increasing demand for energy storage, obtaining aqueous electrolytes that are incombustible, low cost, and conveniently assembled in air with high ionic conductivity has become a dominant focus. Herein, we report the successful synthesis of ultrathin Cu-MOF@δ-MnO2 nanosheets in a controllable way for 2.0 V aqueous electrolyte-based electrochemical capacitors that involve activated carbon. From electrochemical performance tests, the electrode results in a large increase in the performance of an asymmetric supercapacitor, which involves activated carbon, in an operating voltage window from 0 V to 2.0 V in aqueous electrolyte, with a high specific capacitance of 340 F g−1 at a current density of 1.0 A g−1, and cycling stability for 6000 cycles with only a 5% drop in the initial capacitance. The superior performance during the charging–discharging process is attributed to the existence of a film, which can prevent electronic conduction while allowing ionic conduction.