The investigation of inexpensive, effective, environmentally friendly next-generation energy storage devices is an urgent task due to the discontinuities of new generation energy that hinder their further widely application. Among the multitudinous explored energy storage devices, supercapacitors have been regarded as the most potential energy storage systems thanks to their distinctive features of ultralong cycling lifespan, ultrafast charge/discharge process, and high power density compared with batteries and conventional capacitors. Nevertheless, the existing defect of low energy density has always been a bottleneck problem to their long-term development and widespread applications. Meanwhile, the electrodes are the core component in supercapacitors, determining the electrochemical performance directly. Consequently, transition metal oxides were chosen as the promoting materials to design and fabricate appropriately and rationally act as supercapacitor electrodes to harvest the outstanding electrochemical performance of both high energy and power density simultaneously. Here, we summarized the recent advances in transition metal oxides with different dimensions as electrodes for high-performance supercapacitors, including zero-dimensional nanostructures (nanospheres, nanocrystals, nanoparticles), one-dimensional nanostructures (nanorods, nanowires and nanotubes), two-dimensional nanostructures (nanoflakes, nanoplatelets), three-dimensional nanostructures (spherical structure, hollow structure, flower-like structure, honeycomb structure, mesoporous structure), and the corresponding supercapacitors electrochemical performance, expecting to make a thorough inquiry of the relationship between structure and property for highlighting the route to design and synthesis high-performance transition metal oxide-based supercapacitor electrodes.

Recent advances in transition metal oxides with different dimensions as electrodes for high-performance supercapacitors

Janus phenol–formaldehyde resin and periodic mesoporous organic silica nanoadsorbent for the removal of heavy metal ions and organic dyes from polluted water

In-situ constructing visible light CdS/Cd-MOF photocatalyst with enhanced photodegradation of methylene blue

Oxidative degradation of phenols and substituted phenols in the water and atmosphere: a review

Herein, the synthesis of activated carbon (AC)–zeolitic imidazolate framework (ZIF) composite (ACZ) with different amounts of AC was performed to investigate the adsorption of tetracycline pharmaceutical from water. The characterization of the synthesized composites (ACZ) was investigated by SEM, FTIR, XRD, EDS, and BET. The effective parameters on the adsorption of pharmaceutical contaminants including impact pH, contact time, contaminant concentration, and adsorbent dose were investigated. The used composite materials showed good performance in the adsorption of tetracycline. Analysis of isotherm and kinetic data demonstrated that the adsorption process followed the Langmuir model and the second-order kinetic model with correlation coefficients, respectively. According to the studies performed for the removal of tetracycline from the aqueous medium, the maximum removal efficiency and adsorption capacity were 90.5% and 35.64 mg/g, respectively. Due to the high adsorption capacity obtained, the ACZ composite has an acceptable and suitable adsorbent for the removal of pharmaceutical contaminants in effluents. The adsorption of tetracycline is performed by compositing activated carbon on ZIF-8.

Core–shell activated carbon-ZIF-8 nanomaterials for the removal of tetracycline from polluted aqueous solution

As a highly active photocatalyst, g-C3N4/TiO2 heterojunction nanocomposites were in situ synthesized by hydro-thermal method and calcination using melamine as precursors. The morphology and chemical structure of the prepared photocatalysts were characterized by X-ray diffraction, Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), SEM, UV-vis, and photoluminescence analysis (PLA). At last, the photocatalytic activities of g-C3N4/TiO2 nanocomposites to remove fluoride under simulated visible light were evaluated. Results showed that the fluoride removal rate of the prepared g-C3N4/TiO2 was about three times than pure g-C3N4 due to the rapid charge transfer and the efficient separation of photogenerated electron-hole pairs in heterojunctions between g-C3N4 and TiO2. Heterojunction g-C3N4/TiO2 display the excellent fluoride removal rate due to the rapid charge transfer and efficient separation of electron-hole pairs.

Lu Xingyu

Papers

Photocatalytic oxidation removal of fluoride ion in wastewater by g-C 3 N 4 /TiO 2 under simulated visible light