Review on the physicochemical treatments of rice husk for production of advanced materials

Surface water pollution by pharmaceuticals and an alternative of removal by low-cost adsorbents: A review.

Preparation, surface functionalization and application of Fe3O4 magnetic nanoparticles.

Activated bio-chars derived from rice husk via one- and two-step KOH-catalyzed pyrolysis for phenol adsorption.

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

Utilization of wheat bran for producing activated carbon with high specific surface area via NaOH activation using industrial furnace

This study reports the novel dry activation for preparing activated carbon with a high specific surface area from rice husks using solid NaOH. Materials were characterized by N2 adsorption, X-ray diffraction, infrared spectroscopy, and scanning electron microscopy. The effects of mass ratio (1–4) and the activation process (dry activation or impregnation) on the surface area were studied, explicating the mechanism of pore development. With a mass ratio of 3, carbons prepared by dry activation possessed a much higher surface area of 2841 m2/g than the 933 m2/g for impregnation. For the adsorption of phenol, their maximum adsorption capacities were 351.4 and 160.8 mg/g, fitting with the Langmuir model. In addition, the economic analysis estimated a significant gross profit margin of 40.2% for the product. Therefore, it is demonstrated that dry activation is an effective and convenient method for obtaining low cost activated carbon with outstanding surface area.

Novel Method for Preparing Activated Carbons with High Specific Surface Area from Rice Husk

A model of Langmuir monolayer liquid adsorption into effective pores was used to study the monolayer adsorption capacity by theory calculation. The activated carbon (AC) from rice husk with NaOH activation was selected as adsorbent to uptake phenol and methylene blue (MB). Materials were characterized by N 2 adsorption, infrared spectroscopy (IR), and ultraviolet spectrophotometer (UV). In adsorption kinetics, it was observed that the experimental data were well explained by the pseudo second-order equation. Moreover, the Langmuir isotherm was more suitable to explicate results than Freundlich isotherm, implying the monolayer adsorption. Basing on the molecule diameter of 0.72 nm and cross-sectional area of 0.414 nm 2 for phenol, the theoretical adsorption capacities were close to the actual values with small relative error ( 2 ), the sample with wider pores activated at 900 °C exhibited the higher adsorption capacity than AC at 700 °C. And the capillary condensation increased the adsorption capacities, consistent with the order of average pore diameter for ACs. From the model, it indicated that the adsorbent was suitable for adsorption when its critical pore width was two times of adsorbate molecule diameter.

The Langmuir monolayer adsorption model of organic matter into effective pores in activated carbon.

2D MXenes are highly attractive for achieving ultrafast and stable lithium/sodium storage due to their good electric conductivity and abundant redox active sites. While, effective strategies for scalable preparation of oligolayered MXenes are still under exploration. Herein, oligolayered Ti3C2Tx MXene is successfully obtained after conventional synthesis of multilayered Ti3C2 and subsequent delamination process via an organic solvent of tetramethyl-ammonium hydroxide (TMAOH). Comprehensive electrochemical study reveals that surface-controlled redox reaction dominated the charge storage behavior of oligolayered Ti3C2Tx with fast reaction kinetics. Impressively, the obtained oligolayered Ti3C2Tx exhibits excellent lithium/sodium storage performance, featured for a high specific capacity of 330 mAhg−1 at 1.0 Ag−1 after 800 cycles for lithium storage and 280 mAhg−1 at 0.5 Ag−1 after 500 cycles for sodium storage. Such impressive performance will advance the development of oligolayered Ti3C2Tx based materials for lithium/sodium storage and even broaden their application into energy storage.

Ying Zhang

Papers

Utilization of wheat bran for producing activated carbon with high specific surface area via NaOH activation using industrial furnace

Novel Method for Preparing Activated Carbons with High Specific Surface Area from Rice Husk

The Langmuir monolayer adsorption model of organic matter into effective pores in activated carbon.

Oligolayered Ti 3 C 2 T x MXene towards high performance lithium/sodium storage

Facile hydrothermal synthesis of actiniaria-shaped α-MnO2/activated carbon and its electrochemical performances of supercapacitor