Nanoporous Carbon Derived from Green Material by an Ordered Activation Method and Its High Capacitance for Energy Storage

Advances in sustainable nano-biochar: precursors, synthesis methods and applications

Nano-biochar, characterized by its environmentally friendly nature and unique nanostructure, offers a promising avenue for sustainable carbon materials. With its small particle size, large specific surface area, abundant functional groups and tunable pore structure, nano-biochar stands out due to its distinct physical and chemical properties compared to conventional biochar. This paper aims to provide an in-depth exploration of nano-biochar, covering its sources, transformation mechanisms, properties, applications, and areas requiring further research. The discussion begins with an overview of biomass sources for nano-biochar production and the conversion processes involved. Subsequently, primary synthesis methods and strategies for functionalization enhancement are examined. Furthermore, the applications of nano-biochar in catalysis, energy storage, and pollutant adsorption and degradation are explored and enhanced in various fields.

Multifunctional Carbon Dots for Biomedical Applications: Diagnosis, Therapy, and Theranostic

Designing suitable nanomaterials is an ideal strategy to enable early diagnosis and effective treatment of diseases. Carbon dots (CDs) are luminescent carbonaceous nanoparticles that have attracted considerable attention. Through facile synthesis, they process properties including tunable light emission, low toxicity, and light energy transformation, leading to diverse applications as optically functional materials in biomedical fields. Recently, their potentials have been further explored, such as enzyme-like activity and ability to promote osteogenic differentiation. Through refined synthesizing strategies carbon dots, a rich treasure trove for new discoveries, stand a chance to guide significant development in biomedical applications. In this review, the authors start with a brief introduction to CDs. By presenting mechanisms and examples, the authors focus on how they can be used in diagnosing and treating diseases, including bioimaging failure of tissues and cells, biosensing various pathogenic factors and biomarkers, tissue defect repair, anti-inflammation, antibacterial and antiviral, and novel oncology treatment. The introduction of the application of integrated diagnosis and treatment follows closely behind. Furthermore, the challenges and future directions of CDs are discussed. The authors hope this review will provide critical perspectives to inspire new discoveries on CDs and prompt their advances in biomedical applications.

An integrated biorefinery approach for the valorization of water hyacinth towards circular bioeconomy: a review

Water hyacinth (WH) has become a considerable concern for people across the globe due to its environmental and socio-economic hazards. Researchers are still trying to control this aquatic weed effectively without other environmental or economic losses. Research on WH focuses on converting this omnipresent excessive biomass into value-added products. The potential use of WH for phytoremediation and utilizing waste biomass in various industries, including agriculture, pharmaceuticals, and bioenergy, has piqued interest. The use of waste WH biomass as a feedstock for producing bioenergy and value-added chemicals has emerged as an eco-friendly step towards the circular economy concept. Here, we have discussed the extraction of bio-actives and cellulose as primary bioproducts, followed by a detailed discussion on different biomass conversion routes to obtain secondary bioproducts. The suggested multi-objective approach will lead to cost-effective and efficient utilization of waste WH biomass. Additionally, the present review includes a discussion of the SWOT analysis for WH biomass and the scope for future studies. An integrated biorefinery scheme is proposed for the holistic utilization of this feedstock in a cascading manner to promote the sustainable and zero-waste circular bio-economy concept.

Recent Developments of Carbon Dots in Biosensing: A Review

Early diagnosis of diseases is of great importance because it increases the chance of a cure and significantly reduces treatment costs. Thus, development of rapid, sensitive, and reliable biosensing techniques is essential for the benefits of human life and health. As such, various nanomaterials have been explored to improve performance of biosensors, among which, carbon dots (CDs) have received enormous attention due to their excellent performance. In this Review, the recent advancements of CD-based biosensors have been carefully summarized. First, biosensors are classified according to their sensing strategies, and the role of CDs in these sensors is elaborated in detail. Next, several typical CD-based biosensors (including CD-only, enzymatic, antigen-antibody, and nucleic acid biosensors) and their applications are fully discussed. Last, advantages, challenges, and perspectives on the future trends of CD-based biosensors are highlighted.

Efficient Flexible All-Solid Supercapacitors with Direct Sputter-Grown Needle-Like Mn/MnOx@Graphite-Foil Electrodes and PPC-Embedded Ionic Electrolytes

Recent critical issues regarding next-generation energy storage systems concern the cost-effective production of lightweight, safe and flexible supercapacitors yielding high performances, such as high energy and power densities as well as a long cycle life. Thus, current research efforts are concentrated on the development of high-performance advance electrode materials with high capacitance and excellent stability and solid electrolytes that confer flexibility and safety features. In this work, emphasis is placed on the binder-free, needle-like nanostructured Mn/MnOx layers grown onto graphite-foil deposited by reactive sputtering technique and to the polymer gel embedded ionic electrolytes, which are to be employed as new flexible pseudocapacitive supercapacitor components. Microstructural, morphological and compositional analysis of the layers has been investigated by X-ray diffractometer (XRD), Field Emission Scanning Electron Microscope (FE-SEM) and X-ray photoelectron spectroscopy (XPS). A flexible lightweight symmetric pouch-cell solid-state supercapacitor device is fabricated by sandwiching a PPC-embedded ionic liquid ethyl-methylimidazolium bis (trifluoromethylsulfonyl) imide (EMIM)(TFSI) polymer gel electrolyte (PGE) between two Mn/MnOx@Graphite-foil electrodes and tested to exhibit promising supercapacitive behaviour with a wide stable electrochemical potential window (up to 2.2 V) and long-cycle stability. This pouch-cell supercapacitor device offers a maximum areal capacitance of 11.71 mF/cm2@ 0.03 mA/cm2 with maximum areal energy density (Ea) of 7.87 mWh/cm2 and areal power density (Pa) of 1099.64 mW/cm2, as well as low resistance, flexibility and good cycling stability. This supercapacitor device is also environmentally safe and could be operated under a relatively wide potential window without significant degradation of capacitance performance compared to other reported values. Overall, these rationally designed flexible symmetric all-solid-state supercapacitors signify a new promising and emerging candidate for component integrated storage of renewable energy harvested current.