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The demand for the development of high-performance and eco-friendly nanocomposites is soaring up. This is because of their desired mechanical, thermal, electrical, magnetic, catalytic, and optical properties and their ecofriendly development. The diversity of nanocomposites has introduced them to a wide variety of applications such as drug delivery, biosensors, bone regeneration, solar cells, super capacitors, fuel cells, automobiles etc. The nanocomposites are deemed competing materials for the sustainable development, this is because of their ecofriendly behavior and value addition. This manuscript reviews the status of the silicon enhanced nanocomposites, various classes of nanocomposites such as ceramic based matrix nanocomposites, metal-based matrix nanocomposites, Polymer based matrix nanocomposites, etc. advanced green polymer-based nanocomposites and sustainable nanofillers for nanocomposites. The applications of nanocomposites in various sectors such as energy, automobiles, packaging, biomedical, environment and safety have been critically reviewed.

Indigenous hematite iron ore was chemically activated as a function of various hydrogen peroxide concentrations (0.5, 1, 1.5, and 2.0 M), activation time, and iron ore size. Adsorption potential was evaluated at various initial arsenic concentrations, contact time, adsorbent dose, and particle size. Maximum 95% removal efficiency was achieved at 600-μm size of iron ore, activated with 0.5 M concentration of hydrogen peroxide at 24 h of activation time. The experimental data were further evaluated through Langmuir and Freundlich isotherms. The maximum 14.46 mg/g of adsorption capacity was observed through Langmuir isotherm. Moreover, adsorption kinetics was evaluated using pseudo-first-order and pseudo-second-order kinetics, and the intra-particle diffusion model. The kinetics of arsenic adsorption was best described by using the pseudo-first-order kinetics with a kinetic rate of 0.621 min−1. The hematite iron ore before and after arsenic adsorption was characterized by XRD, SEM, and EDX.

This work aims to utilize fly ash from a thermal power station for melanoidin reduction from distillery effluent by adsorption. To accomplish this, coal fly ash was modified through chemical treatment and was then tested for melanoidin adsorption as a function of various melanoidin concentrations, contact time, and pH. The specific novelty of this study is the evaluation of coal fly ash as a low-cost adsorbent for melanoidin removal. Furthermore, the simulation study was carried out using Aspen ADSIM software in order to optimize the commercial usage of the prepared adsorbent. The main results achieved include the maximum removal efficiency of 84% which was reached at initial melanoidin concentration of 1100 mg L−1 (5% dilution), pH 6, and a contact time of 120 min. The Langmuir and Freundlich isotherm models were used to evaluate adsorption isotherms. The maximum adsorption capacity of 281.34 mg/g was observed using the Langmuir isotherm. Furthermore, pseudo-first- and pseudo-second-order and intra-particle diffusion models were used to fit adsorption kinetic data. The pseudo-second-order was best describing the adsorption kinetic with a faster kinetic rate of 0.142 mg g–1 min−1. CFA (coal fly ash) after acidic activation resulted in a slightly higher surface area, average pore volume, and pore size. The maximum breakthrough time and adsorbent saturation time were achieved at initial melanoidin concentration of 1 mol/lit, bed height of 2.5 m, and flow rate of 50 lit/min.

Menthol synthesis is possible through citral and citronellal hydrogenations via following multistage chemical reactions such as hydrogenation and cyclization. This research mainly focuses on a design of selective, active and cost-effective metal-acid (bifunctional) catalysts for menthol production via citral and citronellal hydrogenations. More specifically, Pd and Ni metals were impregnated over acidic support (e.g., hetero-poly acid supported montmorillonite, HPA_MM). The prepared catalysts were characterized by BET, pyridine adsorption and amine titration methods. Some of the most important parameters such as metal type and loading; applied pressure and reaction time have been investigated throughout this work. The obtained results reveals that the 8 wt% Ni-HPA-MM catalyst (Cat-5) has produced 63% menthols (initial reaction rate 0.126 mmol/min) from citral hydrogenation (80 °C, 1.0 MPa) within 24 h. Similarly, during lower applied pressure (0.5 MPa), the production of menthol was significantly improved (approximately 98% of menthol, initial reaction rate ~ 0.138 mmol/min) with the application of 8 wt% Ni-HPA-MM catalyst (Cat-5) in citronellal hydrogenation. Higher menthol selectivity was achieved from both reactions (citral and citronellal hydrogenation) which might be due to the presence of strong Lewis and medium Bronsted acid sites.