Arun Thirumurugan

Cerium oxide (CeO ₂ ) nanoparticles synthesized through a co-precipitation route were characterized by X-ray powder diffraction (XRD), where peak broadening analysis was employed to estimate crystallite size, microstrain, stress and deformation energy density. The Williamson–Hall (W–H) and Scherrer methods were employed to quantify crystallite size and lattice strain. To quantify strain and crystallite size effects, three Williamson–Hall models were employed: The isotropic strain model (W-H-ISM), anisotropic strain model (W-H-ASM) and energy density model (W-H-EDM). These models were applied to XRD-derived W–H plots, revealing distinct microstructural characteristics of the nanoparticles. The W-H-ISM provided an overall estimation of lattice strain, while the W-H-ASM accounted for crystallographic-direction-dependent strain variations. The W-H-EDM further correlated strain energy with defect density. This study advances the fundamental understanding of structure-property relationships in CeO ₂ nanoparticles, providing critical insights for their tailored design in catalytic, energy storage and advanced nanomaterial applications.

Electrochromic devices are evolving from single-function optical modulators into multifunctional platforms capable of regulating light, heat, energy storage, and sensing. In particular, dual-band electrochromic systems that independently modulate visible and near-infrared (NIR) radiation have emerged as a promising strategy for efficient solar spectrum management, addressing the limitation of conventional electrochromic materials that primarily operate in the visible region. This review critically examines recent advances in dual-band electrochromic devices, with emphasis on material design principles that combine redox-induced polaronic absorption with localized surface plasmon resonance (LSPR) in doped and non-stoichiometric metal oxides, hybrid nanocomposites, and molecular assemblies. Beyond material chemistry, we analyze how device architectures including plasmonic heterostructures, metal-dielectric-metal electrodes, Fabry-Perot nanocavities, and self-powered configurations govern spectral selectivity, switching kinetics, and durability. Furthermore, emerging multifunctional electrochromic systems that integrate energy storage, photovoltaics, nanogenerators, and biosensing functionalities are systematically discussed through the lens of electrochemical energy storage and optical modulation. By identifying key performance trade-offs between optical contrast, charge capacity, cycling stability, and scalability, this review provides a framework for rationally designing next-generation multifunctional electrochromic devices toward practical smart window, display, and energy-adaptive applications.

Combining electrochemical and advanced oxidation processes (AOPs) has greatly mitigated the limitations of electrocoagulation (EC) in water treatment. This study examined the effectiveness of sonolysis (US)‐assisted alternating current (AC)–EC in reducing fluoride (F¯) from landfill leachate wastewater (LLW), with measurements of electrical energy consumption (EEC). The experimental results indicated that the US‐assisted AC–EC (US+AC–EC) process achieved greater reduction in F¯ from wastewater. To treat LLW, the US+AC–EC process different operational parameters were optimized using response surface methodology (RSM) based on central composite design (CCD). The effects of five independent parameters, such as sonication power (A) and pulse duty cycle (B), F¯ concentration (C) and current density (D), and reaction time (E) on F¯ reduction (%) and EEC were studied. A quadratic model was used to predict the decrease of F¯ and EEC under various conditions. ANOVA, or analysis of variance, was used to assess the significance of independent variables and their interactions. The optimal conditions for achieving maximum reduction of F¯ and the least amount of EEC were determined using statistical and mathematical methods. The optimal conditions for achieving the maximum amount of F¯ (81%) removed with the minimum amount of EEC (8.64 kWh/m ³ ) include the following: A—60 W, B—0.45, C—12 mg/L, D—0.6 A/dm ² , and E—22.50 min. The US+AC–EC process has proved to be an effective and efficient method for removing F¯ from LLW with the least amount of EEC and that CCD is a viable method for improving the process. In conclusion, the US+AC–EC process has the potential to efficiently remove contaminants from wastewater.

All over the world, individuals are worried about the availability of safe drinking water and sanitation. According to the United Nations, there are billions of people who do not have access to clean drinking water. If not adequately treated, wastewater from industrial, domestic, and agricultural operations can harm water quality, human health, and aquatic ecosystems. Electrochemical wastewater treatment technologies are effective, selective, and disinfect in‐situ because of their electrochemical nature. This study aimed to assess the usability and effectiveness of indirect‐electrochemical oxidation (IEO) methods for distillery industrial wastewater (DIW) by measuring treatment efficiency and consumption of electrical energy (CEE). The impact of operational parameters, such as current (0.07–3.4 Amp), pH (3–11), chemical oxygen demand (COD) (500–2500 mg L ⁻¹ ), supporting electrolyte concentration (SEC) (2–10 g L ⁻¹ ), types of electrolyte (NaCl, KCl, Na ₂ SO ₄ , and Na ₂ CO ₃ ), and electrode gap (2–4 cm), on the removal of % COD and CEE were investigated. The most effective electrolyte was found to be NaCl. The experiments with COD = 1000 mg L ⁻¹ , SEC = 6 g L ⁻¹ , stirring speed (SS) = 300 rpm, electrode gap (EG) = 2 cm, current = 0.27 Amp, and pH = 6 were established as the optimum level. For these conditions, it was observed that the COD removal was 85% and CEE was 19.38 kWhr kg COD ⁻¹ , respectively. After a period of 6 h of operation, it has been observed that the IEO process offers a significant removal efficiency with respect to the parameters of operation for wastewater. The UV/Vis‐spectrophotometer was employed to evaluate the color removal and oxidation of organic compounds. As a result of the experimental results, the IEO process appears to be a better technology for eliminating contaminants from wastewater while using required electrical energy.