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The sol–gel process enables the preparation of silica-based matrices with tailored composition and properties that can be used in a variety of applications, including catalysis, controlled release, sensors, separation, etc. Commonly, it is assumed that silica matrices prepared via the sol–gel synthesis route are "inert" and, therefore, do not affect the properties of the substrate or the catalyst. This short review points out that porous silica affects the properties of adsorbed/entrapped species and, in some cases, takes an active part in the reactions. The charged matrix affects the diffusion of ions, thus affecting catalytic and adsorption processes. Furthermore, recent results point out that ≡Si-O. radicals are long-lived and participate in redox processes. Thus, clearly, porous silica is not an inert matrix as commonly considered. [ABSTRACT FROM AUTHOR]

The demand for display devices increased very rapidly, and out of various display techniques, field emission-based display technology has huge potential to make next-generation display devices. A conventional field emitter uses single materials, which offer high quantum resistance between the emitter materials and substrate; thus, the heterostructure formation can be used for the reduction of quantum resistance by increasing the density of state near the Fermi level. Therefore, in the present work, black phosphorus (BP)/dysprosium hexaboride (DyB6) heterostructures were used for field emission study. Here, BP was synthesized via a solvothermal route. The microstructural analysis of black phosphorus shows rod-like morphology of ∼1 μm length and ∼200 nm width. Apart from the BP, DyB6 cubes of ∼100 nm were synthesized at 1000 °C in an argon atmosphere. The synthesized samples were used for making dispersion, and the as-prepared dispersion was used for the fabrication of films over a silicon substrate using a spin coating method. For the first time, field emission of BP/DyB6 heterostructure films has been performed and hybrid structures show an enhanced enhancement factor (β = 2624) and a low turn-on field (3.74 V/μm). Mechanistic insights into the possible origin of enhanced. [ABSTRACT FROM AUTHOR]

Dip‐pen nanolithography (DPN) is a powerful and unique technique for precisely depositing tiny nano‐spherical cap shapes (nanoclusters) onto a desired surface. In this study, a meta‐chemical surface (MCS; a pattern with advanced features) is developed by DPN and applied to electrochemical lead sensing, yielding a calibration curve in the ppb range. An ink mixture of PMMA and NTPH (which binds to Pb (II), as supported by DFT calculations) is patterned over a Pt surface. The average height of the nanoclusters is ≈13 nm with a high surface area‐to‐volume ratio, which depends on the ink composition and the MCS surface. This ratio affected the sensitivity of the MCS as a detecting tool. The results indicate that the sensor's features can be controlled by the ability to control the size of the nanoclusters, attributed to the unique properties of the DPN production method. These results are significant for the water‐source purification industry. [ABSTRACT FROM AUTHOR]

Considering the challenges posed by agricultural waste, specifically rice straw, this study focuses on implementing cost-effective and eco-friendly processes to transform rice straw waste intovaluable, high-demand materials (sodium carbonate and M-25 concrete). The analysis of rice straw reveals its primary composition of cellulose and sodium silicate, with a layered cellulose microstructure. To produce sodium carbonate, rice straw is subjected to incineration ina furnace, with the resulting effluent gas passing through aqueous NaOH to effectively capture CO2 at room temperature and ambient pressure. Simultaneously, the ash generated from burning rice straw is employed as a pozzolanic material in the production of M25 grade concrete. Notably, the concrete containing 20% ash demonstrates an impressive compressive strength of 29.05 MPa after a 28-day curing period. These results are highly promising for the potentialutilization of agricultural waste in the production of soda and concrete. [ABSTRACT FROM AUTHOR]

Electrochemical Cl2 generation using inexpensive electrocatalysis has drawn tremendous scientific attention to meet the future demand for chlorine. The present work deals with the design of the chemical process to synthesize anisotropically aligned metallic hcp‐cobalt nanoparticles. The as‐obtained hcp‐cobalt rods are utilized for the generation of O2 and Cl2 via an electrochemical process. Controlling the thermodynamic parameters during the thermal decomposition of cobalt oxalate rods leads to the formation of aligned nanoparticles. Detailed microscopic investigation shows that the slow heating rate favors the anisotropic growth of nanoparticles, and the fast‐heating rate leads to the formation of agglomerated nanoparticles. Anisotropically aligned hcp‐Co rods show an overpotential of 240 and 30 mV for O2 and Cl2 evolution, respectively. These findings elaborate that aligned particles (rod‐like structures) show promising electrocatalysts with better efficiency for O2 and Cl2 generation. Further, wastewater treatment is done by using in situ generated chlorine and 99% degradation efficiency is observed for textile effluents (methyl orange). [ABSTRACT FROM AUTHOR]

Hydrothermal method for the synthesis of hematite (α‐Fe2O3) has been done at 120 °C. Morphological study reveals the formation of spherical nanoparticles of average size ∼10 nm. The prepared electrode (Fe2O3 dropcosted over graphite sheet) used as a working electrode for the oxygen evolution reaction in 1 M KOH. The linear sweep voltammetry confirms that the as‐prepared electrode requires 340 mV potential to reach a current density of 1 mA/cm2 and 510 mV potential for 10 mA/cm2. Further, the kinetics of electrocatalyst has been investigated using Tafel slope, mass activity and Turn over frequency. [ABSTRACT FROM AUTHOR]