The efficient CO2 capture requires engineering a low-cost, highly efficient adsorbent. Herein, the upcycling of waste floral foam into chemically activated nanoporous carbon (CANC) is reported. The implications of the impregnation ratio of KOH on the porosity, surface functionality of CANC, and its role in CO2 capture are examined and discussed. The optimized sample, CANC-2 (SSA 1043 m2/g), with a large ultra-micropore volume and higher oxygen and nitrogen content, demonstrates 3.71 mmol/g CO2 capture capacity at 15 degrees C and 1 atm. The framework provided here offers a technique for tuning the attributes of nanoporous carbon favorable for CO2 capture. Ultimately, the pollution control of solid polymeric waste can be done by upcycling it into value-added products which further utilized in environmental applications.

In the previous years, activated carbons (ACs) derived from agro-waste have demonstrated excellent adsorption capability. Production of ACs using easy available and low cost agro-waste marks them as unique materials for several environmental applications including but not limited toCO2capture, dyes and heavy metal ion removal by adsorption etc. This review highlights the present scenario of available agricultural land, global agricultural production and generation of enormous agro-waste worldwide with their alternative management by producing value-added and applicable ACs as an adsorbent for environmental remediation instead of burning. This review specifically aims to support researchers by providing an all-inclusive overview of different aspects of agro-waste management with a perspective in AC preparation, characterization and its environmental applications such as CO2 capture, dye and metal ion adsorption for enhancing the pathways to clean air and water.

Oxygen evolution reaction (OER) plays a vital role in the field of water splitting, which has a promising way of achieving high efficiency and clean energy. However, a large overpotential and sluggish kinetics limit the water splitting efficiency. Thus, development of effective electrocatalyst is a key point to make OER more practicable. In this communication, we account a metal–organic framework (MOF) pyrolization path for derived Cu-embedded porous carbon materials as electrocatalyst for efficient and superior OER application in an alkaline condition. The prominent effect of pyrolysis was observed on the porosity as well as Cu content which predominates its electrocatalytic properties. The rise in pyrolysis temperature decreases surface area (SSA) due to more contribution of macroporosity. The hybrid Cu2O/Cu connected porous carbon form of the CuBTC C600 provides large channels for rapid electron transfer and beneficial for electrolyte penetration which enhances the catalytic property results in to a low overpotential of 310 mV @10 mA/cm2 and Tafel slope (80 mV dec−1), and exceptional long-term stability as compared to CuBTC and rest materials. The role of porosity and consortium effect of Cu NPs and Cu2O along with effect of pyrolysis was studied and discussed. Comparative LSV curves of CuBTC and its derived electrocatalyst, recorded in 1.0 M KOH at a scan rate of 10 mV/s.

Currently, carbon dots (CDs) have emerged as effective and viable sensing probes for detection of drugs owing to their exceptional fluorescence properties. Herein, the present work proposes the green synthesis of CDs using cannon ball (Couropita guianesis) flower petals which is further utilized as the analytical probe for detection of metformin (MTF) drug. The synthesized cannon ball carbon dots (CBCDs) exhibits 1.5 to 3.0 nm size with polycrystalline nature. The obtained CBCDs possess significant fluorescence property at 240 nm. Further, the prepared CBCDs demonstrate potential for sensing MTF in the range 5 µmolL−1 to 50 µmolL−1, with low detection limit of 0.79 µmolL−1 and low quantization limit of 2.3988 µmolL−1. The proposed work offers excellent, cost-effective and sustainable sensing probe for the quantitative detection of MTF.

The discovery of a cutting-edged electrocatalyst for water-splitting is an immense challenge to developing metal-air batteries and fuel cells. Therefore, developing sophisticated electrocatalysts with high activity and stability based on non-noble metal elements remains a great challenge. Herein, we prepared efficient polyhedral Ni/Cu bimetallic MOFs that are synthesized by a simple solvothermal method, in which the incorporation of Ni enhances the electrocatalytic properties of CuBTC MOF with distinct molar ratios. Benefiting from the unique morphology, and the favourable effect of Ni incorporation, the polyhedral Ni/Cu bimetallic MOFs exhibit conspicuous efficiency towards OER. The optimized NiCuBTC (2 : 8) bimetallic MOF exhibited superior activity with an overpotential of 290 mV to reach the current density of 10 mA cm-2. Moreover, the NiCuBTC (2 : 8) MOF also shows better long-term stability. The present work shows a facile strategy to design and synthesize a NiCuBTC (2 : 8) MOF electrocatalyst, which offers superior electrocatalytic performance towards water electrocatalysis. We prepared efficient polyhedral Ni/Cu bimetallic MOFs that are synthesized by a simple solvothermal method, in which the incorporation of Ni enhances the electrocatalytic properties of CuBTC MOF with distinct molar ratios.

The conversion of waste into value added products is the way of agro-waste management. Herein, banana pseudo stem fibre was modified by partial bleaching to sustain its strength and aesthetic properties. The obtained fibres employed for the removal of Reactive Red 195 from an aqueous solution followed by its sustainable application for futuristic spinnable yarn and composite material for industrial applications. The raw banana fibre (RBF), modified banana fibre (MBF) and banana fibre remaining after dye adsorption (BFADA) were all characterised to determine their morphology, structural functionality, tensile strength, and microbial load. The modified banana fibre adsorbs 23.57 mg g(-1) of Reactive Red 195 dye at pH 2 in 60 min. It was able to remove 61% of residual Reactive Red 195 dye from the water remaining after cotton dyeing. The fibre after adsorption demonstrated remarkable durability against both dry and wet rubbing. Additionally, it showcased exceptional efficacy in combating both gram-positive and gram-negative microbial burdens. The BFADA sample is reused in the form of composite material for futuristic industrial applications by characterizing its property in terms of strength. The current approach proposes MBF as a low-cost bio material for the removal of dyes from textile effluent and its reuse in the other value added products with improved textile and fractural strength.

This study proposes upcycling polymeric waste, i.e., waste floral foam, into high-performance nanoporous carbon that efficiently captures CO2. This paper presents strategies for improving the properties of nanoporous carbon, which aid in a superior CO2 capture performance. Initially, pristine nanoporous carbon was produced from waste floral foam using various KOH impregnation ratios. The nanoporous carbon with a 1:2 (waste floral foam:KOH) ratio exhibiting optimal CO2 capture capability was further advanced through single and dual atom doping. The doping of N and codoping of N,S atoms into the nanoporous carbon altered its textural and surface chemical properties, making them efficient for CO2 capture. Comparative CO2 capture studies of pristine nanoporous carbon (NC-x), N-doped nanoporous carbon (N-NC2), and N,S-codoped nanoporous carbon (N,S-NC2) demonstrate the superiority of N-doping. N-doped nanoporous carbon exhibited the largest ultramicroporosity (0.3100 cm3/g, 63.43%) and highest heteroatom content (34.94 atomic %), contributing to its enhanced CO2 capture capability (4.54 mmol/g). Implementing the "waste-to-depollution" approach, this research lays the groundwork for producing low-cost, environmentally friendly nanoporous carbon with remarkable CO2 capture attributes.

The rise in universal population and accompanying demands have directed toward an exponential surge in the generation of polymeric waste. The estimate predicts that world-wide plastic production will rise to approximate to 590 million metric tons by 2050, whereas 5000 million more tires will be routinely abandoned by 2030. Handling this waste and its detrimental consequences on the Earth's ecosystem and human health presents a significant challenge. Converting the wastes into carbon-based functional materials viz. activated carbon, graphene, and nanotubes is considered the most scientific and adaptable method. Herein, this world provides an overview of the various sources of polymeric wastes, modes of build-up, impact on the environment, and management approaches. Update on advances and novel modifications made in methodologies for converting diverse types of polymeric wastes into carbon nanomaterials over the last 5 years are given. A remarkable focus is made to comprehend the applications of polymeric waste-derived carbon nanomaterials (PWDCNMs) in the CO2 capture, removal of heavy metal ions, supercapacitor-based energy storage and water splitting with an emphasis on the correlation between PWDCNMs' properties and their performances. This review offers insights into emerging developments in the upcycling of polymeric wastes and their applications in environment and energy.

The current study involves the value-based conversion of waste floral foam into nanoporous activated carbon (NAC), which can be employed as a bifunctional material as a CO2 adsorbent and an electrode for supercapacitors. The waste floral foam is first subjected to acid pickling and then thermally activated at various temperatures (500–800 °C) under a N2 atmosphere. The resultant optimum sample, NAC700, has a high surface area of 732 m2/g, an abundance of narrow micropores (≤0.8 nm), and rich surface oxygen functionality. Owing to its array of synergistic attributes, the optimum sample NAC700 exhibits an excellent CO2 capture capacity of 3.22 mmol/g at 15 °C and 1 bar. Simultaneously, NAC700 also delivers a good specific capacitance of 116 F/g at 5 mV/s and 187 F/g at 0.2 A/g, as calculated from CV and GCD data, respectively, in 1 M KOH. The strategy proposed here offers a facile pore manipulation technique for fabricating nanoporous activated carbon with substantial potential for CO2 capture and energy storage applications while neutralizing waste floral foam.

This work reports an efficient method for facile synthesis of hierarchically porous carbon (WB-AC) utilizing wheat bran waste. Obtained carbon showed 2.47 mmol g-1 CO2 capture capacity with good CO2 /N2 selectivity and 27.35 to 29.90 kJ mol-1 isosteric heat of adsorption. Rapid removal of MO dye was observed with a capacity of ~555 mg g-1 . Moreover, WB-AC demonstrated a good OER activity with 0.35 V low overpotential at 5 mA cm-2 and a Tafel slope of 115 mV dec-1 . It also exhibited high electrocatalytic HER activity with 57 mV overpotential at 10 mA cm-2 and a Tafel slope of 82.6 mV dec-1 . The large SSA (757 m2  g-1 ) and total pore volume (0.3696 cm3  g-1 ) result from N2 activation contributing to selective CO2 uptake, high and rapid dye removal capacity and superior electrochemical activity (OER/HER), suggesting the use of WB-AC as cost effective adsorbent and metal free electrocatalyst.