Dongya Sun

Bio: Dongya Sun is an academic researcher from Xiamen University of Technology. The author has contributed to research in topics: Layered double hydroxides & Supercapacitor. The author has an hindex of 5, co-authored 8 publications receiving 70 citations.

ZnGaNO Photocatalyst Particles Prepared from Methane-Based Nitridation Using Zn/Ga/CO3 LDH as Precursor

Abstract: Methane-based nitridation was employed to produce wurtzite zinc-gallium oxynitride (ZnGaNO) photocatalyst particles using Zn/Ga/CO3 layered double hydroxides (LDHs) as precursor. Introduction of methane to nitridation would promote the formation of Zn–O bonding and suppress shallow acceptor complexes such as V(Zn)-Ga(Zn) and Ga-Oi in ZnGaNO particles. On the other hand, high flow rate of methane would induce breaking of Ga–N bonding and enhance surface deposition of metallic Ga atoms. After loading with Rh and RuO2, ZnGaNO particles had free electron density in an order of S50 > S20 > S90 > S0, which correlated well with their photocatalytic performance upon visible-light irradiation. The best performance of the loaded S50 was ascribed to the relatively flat surface band bending of the particle. Methane-based nitridation of Zn/Ga/CO3 LDHs would provide a new route to tune the surface chemistry of ZnGaNO and enhance the photocatalytic performance to its full potential.

Structure and Electrochemical Properties of Mn3O4 Nanocrystal-Coated Porous Carbon Microfiber Derived from Cotton

Abstract: Biomorphic Mn3O4 nanocrystal/porous carbon microfiber composites were hydrothermally fabricated and subsequently calcined using cotton as a biotemplate. The as-prepared material exhibited a specific capacitance of 140.8 F·g−1 at 0.25 A·g−1 and an excellent cycle stability with a capacitance retention of 90.34% after 5000 cycles at 1 A·g−1. These characteristics were attributed to the introduction of carbon fiber, the high specific surface area, and the optimized microstructure inherited from the biomaterial.

Recent progress in carbon-based materials for supercapacitor electrodes: a review

Abstract: Increased energy consumption stimulates the development of various energy types. As a result, the storage of these different types of energy becomes a key issue. Supercapacitors, as one important energy storage device, have gained much attention and owned a wide range of applications by taking advantages of micro-size, lightweight, high power density and long cycle life. From this perspective, numerous studies, especially on electrode materials, have been reported and great progress in the advancement in both the fundamental and applied fields of supercapacitor has been achieved. Herein, a review of recent progress in carbon materials for supercapacitor electrodes is presented. First, the two mechanisms of supercapacitors are briefly introduced. Then, research on carbon-based material electrodes for supercapacitor in recent years is summarized, including different dimensional carbon-based materials and biomass-derived carbon materials. The characteristics and fabrication methods of these materials and their performance as capacitor electrodes are discussed. On the basis of these materials, many supercapacitor devices have been developed. Therefore, in the third part, the supercapacitor devices based on these carbon materials are summarized. A brief overview of two types of conventional supercapacitor according to the charge storage mechanism is compiled, including their development process, the merits or withdraws, and the principle of expanding the potential range. Additionally, another fast-developed capacitor, hybrid ion capacitors as a good compromise between battery and supercapacitor are also discussed. Finally, the future aspects and challenges on the carbon-based materials as supercapacitor electrodes are proposed.

Dual-acting cellulose nanocomposites filled with carbon nanotubes and zeolitic imidazolate framework-67 (ZIF-67)–derived polyhedral porous Co3O4 for symmetric supercapacitors

Abstract: Conforming to sustainable development trend, natural material cellulose has been extensively studied in the field of energy storage. However, its low conductivity is a huge obstacle to its application in supercapacitors. Integrating nanocellulose as a green binder with conductive materials achieves the efficient use of natural resources. Here, carbon nanotubes (CNTs) were embedded in porous Co3O4 (PCO) dodecahedrons in situ derived from zeolitic imidazolate framework-67 (ZIF-67), for which the morphologies of the composites were considerably remained at the dodecahedron. The main pseudo-capacitive materials are regulated by different amounts of CNTs to modify the morphology and enhance the conductivity. For electrode materials, the charming structure of PCO-CNTs (PCC) with multichannels allows efficient electron transfer, which brings about a competent utilization of redox active sites in PCO. What is more worth mentioning is that the nanocellulose-PCC nanocomposites with good processing properties were used to form binder-free electrodes. Given the fine designed structure and good electrochemical performance, the electrodes were assembled into symmetric supercapacitors, showing high areal capacitance, energy, and power density. The preparation of composites based on PCC and nanocellulose provides a new way to develop sustainable energy storage devices.