Xinran Li

N,S co-doped 3D mesoporous carbon–Co3Si2O5(OH)4 architectures for high-performance flexible pseudo-solid-state supercapacitors

Ultrathin Co2Si2O5(OH)4 flakes were grown on mesoporous carbon frameworks via two simple steps of calcination and hydrothermal treatment with natural bamboo leaves as the renewable silica source. More importantly, the existence of carbon frameworks co-doped with nitrogen and sulfur could offer large specific capacitance due to their possible faradaic reactions. The combination of porous carbon frameworks derived from natural bamboo leaves and the layer structures of silicate leads to plentiful ion channels. These possible reasons made the materials show a high performance as supercapacitor electrode materials when tested in 3.0 M aqueous KOH solution with a three-electrode system. In 3.0 M KOH solution, the specific capacitance of the electrode is 1600 F g−1 under the current density of 1.0 A g−1. The as-assembled pseudo-solid state device also showed a high specific capacitance of 352 mF cm−2 under a current density of 1.0 mA cm−2, and retained about 97.2% of the initial capacity after 6000 cycles. Moreover, it exhibited excellent mechanical flexibility when bending the device at different angles, and even after 1000 cycles the specific capacitance was stable. The long cycle life and high specific capacitance of the ultrathin flakes made them a great potential candidate for supercapacitor electrodes.

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.

Mesoporous uniform ammonium nickel phosphate hydrate nanostructures as high performance electrode materials for supercapacitors

Mesoporous uniform ammonium nickel phosphate hydrate nanostructures are successfully prepared by a one-pot hydrothermal method. As a result of the unique feature of large surface area (418 m2 g−1) and tunable mesostructures, the material exhibits good performance as supercapacitor electrodes, with a specific capacitance of 1072 F g−1 in 3.0 M KOH at a current density of 1.50 A g−1, and show a good cycle life which does not obviously decay after 3000 cycles (the retention 95.0% of initial specific capacitance after 3000 cycles).

Noble metal-based materials in high-performance supercapacitors

Noble metal-based materials have been intensively investigated as good additives of electrode materials for supercapacitors, since they can improve the specific capacitance, conductivity, and chemical and thermal stabilities of the electrode materials. This review carefully summarizes noble metal-based materials for high-performance supercapacitor electrodes. The advances of hybrid electrodes are then assessed to include hybrid systems of noble metal-based materials with compounds such as carbonaceous materials, metals and transition metal oxides or hydroxides. A variety of synthetic methods such as hydrothermal/solvothermal methods, polymerization, and electrodeposition methods are also discussed to prepare noble metal-based materials. This review comprehensively summarizes and evaluates the recent progress in the research on noble metal-based electrode materials for supercapacitors, including synthesis methods, electrochemical performances, and related devices.

Metal (M = Co, Ni) phosphate based materials for high-performance supercapacitors

With the ever increasing demand for clean, sustainable energy, electrochemical supercapacitors with the advantages of high power density, high efficiency and long life expectancy have become one of the major devices for energy storage and power supply, and have found wide application in hybrid power sources, backup power sources, starting power for fuel cells and burst-power generation in electronic devices. Metal phosphates with the advantages of abundance, environmental friendliness and low cost are emerging as a novel class of promising electrode materials for supercapacitors. This review summarizes recent progress with respect to cobalt and nickel phosphate based micro/nanomaterials applied as supercapacitors, covering ammonium/bimetallic phosphates, cobalt phosphates, nickel phosphates and cobalt/nickel phosphates. Much progress has been made using metal phosphate materials as supercapacitors; however, there is still much room for further improvement.

Ferric Phosphate Hydroxide Microcrystals for Highly Efficient Visible-Light-Driven Photocatalysts

Fe4(OH)3(PO4)3 microcrystals are successfully synthesized by a simple hydrothermal method. Due to a possible self-etching mechanism, different morphologies of Fe4(OH)3(PO4)3 microcrystals are obtained. Several reactions with different temperatures and times are performed to confirm the supposed self-etching mechanism. Moreover, as a result of their different micro/nanostructures, these microcrystals present different photocatalytic activities for visible-light-driven photodegragadation of methylene blue.