The exploration of renewable, cost-effective, and environmentally friendly electrode materials with high adsorption, fast ion/electron transport, and tunable surface chemistry is urgently needed for the development of next-generation biocompatible energy-storage devices. In recent years, biomass-derived carbon electrode materials for energy storage have attracted significant attention because of their widespread availability, renewable nature, and low cost. More importantly, their inherent uniform and precise biological structures can be utilized as templates for fabricating electrode materials with controlled and well-defined geometries. Meanwhile, the basic elements of biomass are carbon, sulfur, nitrogen, and phosphorus. The special naturally ordered hierarchical structures as well as abundant surface properties of biomass-derived carbon materials are compatible with electrochemical reaction processes such as ion transfer and diffusion. To date, a series of novel porous carbon materials with different dimensions have been prepared by various methods using biomass as the raw material, which is an important field in the fabrication of supercapacitor electrode materials. Herein, we summarized recently reported biomass-derived carbon materials with one-dimensional, two-dimensional, and three-dimensional structures and their applications as carbon-based electrode materials for supercapacitors. Finally, the current challenges and future perspectives of the carbon-based electrode materials with respect to the supercapacitor's performance were closely highlighted.

Biomass-derived porous carbon materials with different dimensions for supercapacitor electrodes: a review

Transition metal based battery-type electrodes in hybrid supercapacitors: A review

Biomass derived interconnected hierarchical micro-meso-macro- porous carbon with ultrahigh capacitance for supercapacitors

A three-dimensional hierarchical porous carbon is synthesized via a facile chemical activation route with garlic skin as the precursor and KOH as the activating agent. The as-obtained carbon presents a high specific surface area of 2818 m2 g−1 and a hierarchical porous architecture containing macroporous frameworks, mesopores (2–4 nm), and micropores (0.6–1.0 nm). As the electrode material for a supercapacitor, due to its unique interconnected porous structure, this garlic skin-derived carbon exhibits excellent electrochemical performance and cycling stability. At a current density of 0.5 A g−1, the capacitance is up to 427 F g−1 (162 F cm−3). Even at a high current density of 50 A g−1, the capacitance can be maintained to a high value of 315 F g−1 (120 F cm−3). After charging–discharging at a current density of 4.5 A g−1 for 5000 cycles, the capacitance retention is as high as 94%. The results suggest that this garlic skin-derived 3D hierarchical porous carbon is a promising electrode material for high-performance supercapacitors.

Synthesis of garlic skin-derived 3D hierarchical porous carbon for high-performance supercapacitors

Photoreduction of N₂ is among the most interesting and challenging methods for N₂ fixation under mild conditions. In this study, we determined that nitrogen vacancies (NVs) could endow graphitic carbon nitride (g-C₃N₄) with the photocatalytic N₂ fixation ability. Photocatalytic N₂ fixation induced by NVs is free from the interference of other gases. The reason is that NVs could selectively adsorb and activate N₂ because NVs have the same shape and size as the nitrogen atom in N₂. In addition to this, NVs could also improve many other properties of g-C₃N₄ to support photocatalytic N₂ fixation. These new findings could elucidate the design of efficient photocatalysts for photocatalytic N₂ fixation.

Selective photocatalytic N₂ fixation dependent on g-C₃N₄ induced by nitrogen vacancies

Summary Two-dimensional materials with abundant in-plane pores (porous 2D materials) have shown high performances as catalysts, especially for photocatalysis and electrocatalysis, owing to their distinct microstructural advantages originating from both 2D materials and porous materials. Here, the recent progress in porous 2D materials in photocatalysis and electrocatalysis is reviewed. We first highlight the influence of their special structural merits on the processes of photocatalysis and electrocatalysis, including transport of ion and/or charge carriers, surface active sites, stability, modifications, electronic band structure, and light absorption properties. Representative synthetic methods for porous 2D materials are also introduced classified by top-down and bottom-up routes. In addition, their applications in different aspects of photocatalysis and electrocatalysis are presented systematically. In conclusion, we propose some opportunities and challenges for the development of porous 2D materials, with the hope of further facilitating the applications of these emerging advanced materials in photocatalysis and electrolysis.

https://www.cell.com/matter/pdf/S2590-2385(20)30173-9.pdf

Porous Two-Dimensional Materials for Photocatalytic and Electrocatalytic Applications

Continuous ongoing development of dense integrated circuits requires significant advancements in nanoscale patterning technology. As a key process in semiconductor high volume manufacturing (HVM), high resolution lithography is crucial in keeping with Moore's law. Currently, lithography technology for the sub-7 nm node and beyond has been actively investigated approaching atomic level patterning. EUV technology is now considered to be a potential alternative to HVM for replacing in some cases ArF immersion technology combined with multi-patterning. Development of innovative resist materials will be required to improve advanced fabrication strategies. In this article, advancements in novel resist materials are reviewed to identify design criteria for establishment of a next generation resist platform. Development strategies and the challenges in next generation resist materials are summarized and discussed.

Extreme ultraviolet resist materials for sub-7 nm patterning

The use of bio-nanotechnology for the fabrication of diverse functional nanomaterials with precisely controlled morphologies and microstructures is attracting considerable attention due to its sustainability and renewability. As one of the key energy storage devices, supercapacitor (SC) requires the active electrode material to have high specific surface area, interconnected porous structure, excellent electronic conductivity, and appropriate heteroatom doping for promoting the transfer of electrons and electrolyte ions. The combination of bio-technology and SC will open up a new avenue for the large-scale fabrication of high performance functional energy storage devices. In this review, the most state-of-the-art research progress in bio-nanotechnological fabrication of different nanomaterials, including carbon materials, metal oxides, conducting polymers, and their corresponding composites are reviewed with the following three bio-nanotechnical approaches covered: (1) biomass carbonization technologies; (2) bio-template methods; and (3) bio-complex technologies, while also highlighting their applications as functional SC electrodes.

Shulan Wang

Papers

Transition metal based battery-type electrodes in hybrid supercapacitors: A review

Biomass derived interconnected hierarchical micro-meso-macro- porous carbon with ultrahigh capacitance for supercapacitors

Porous Two-Dimensional Materials for Photocatalytic and Electrocatalytic Applications

Extreme ultraviolet resist materials for sub-7 nm patterning

Bio‐Nanotechnology in High‐Performance Supercapacitors