Mou Pal

The efficient removal of organic dyes is essential for wastewater remediation. In this study, we report the synthesis of cerium oxide (CeO ₂ ) nanoparticles via alkaline precipitation, using ethylene glycol (EG) as a complexing agent to tailor structural and surface properties. XRD and Raman analyses confirmed a fluorite‐type cubic phase, with a decrease in average particle size from 15 to 9 nm upon EG addition. The surface area, Ce ⁴⁺ /Ce ³⁺ ratio, surface hydroxyl groups and the concentration of oxygen vacancies were found to be directly influenced by the use of EG. CeO ₂ nanoparticles predominantly exhibited a spherical morphology along with a few nanorods. The EG‐assisted CeO ₂ exhibited superior efficiency for the adsorption and photocatalytic degradation of acid orange 7 (AO7) under UV radiation. This enhanced performance is attributed to the synergistic effects of increased active sites and surface charge. Radical scavenging experiments identified radicals as the primary active species, with •OH radicals and holes playing secondary roles. CeO ₂ catalyst could be reused up to four cycles without significant loss of activity. These findings highlight that EG‐assisted synthesis effectively tailors CeO ₂ properties to improve its performance in remediation of emerging pollutants.

Wind energy implementation in low-wind regions remains highly uncertain due to the inherent variability and stochastic nature of wind speed. This study proposes a comprehensive statistical-stochastic framework to address this challenge and demonstrates its applicability through a case study in Puebla, Mexico, using hourly data from three representative sites: Puebla, Tehuacán, and Izúcar. A wide range of classical, generalized, and mixture probability density functions (PDFs) is evaluated, showing that multi-parameter models significantly outperform conventional approaches in capturing complex wind regimes. Temporal analysis reveals a clear dual periodicity (diurnal and seasonal), while long-range dependence is identified through the climacogram and Hurst exponent, successfully reproduced using fractional Gaussian noise (fGn).Based on the modeled wind series, the performance of a small-scale wind turbine (Aeolos-V; 1 kW) is evaluated. Results indicate limited wind energy potential, with capacity factors of ~1% in Puebla and Izúcar and up to 8% in Tehuacán, the latter approaching the upper range typically reported for small wind systems at low hub heights. Accordingly, annual energy production remains modest (< 700 kWh/year), directly affecting economic viability. The levelized cost of electricity (LCOE) is one to two orders of magnitude higher than conventional electricity tariffs in Mexico (0.10-0.20 USD/kWh), even under optimistic investments scenarios, indicating poor economic competitiveness. However, measurable CO2 emission reductions are achieved, highlighting the environmental benefits of distributed wind systems. Overall, viability in low-resource regions is primarily constrained by capacity factor, emphasizing the importance of careful site selection and hybrid energy strategies.

This study presents an in-depth computational analysis of hybrid organic-inorganic lead halide perovskite solar cells (PSCs) with a composition of Cs0.17FA0.83Pb(Br0.4I0.6)3 (FA: formamidinium) material under cool and warm light-emitting diodes (LEDs). We propose a novel design of an inverted (p-i-n) PSC to compare the power conversion efficiencies (PCEs) of opaque and semitransparent models under the AM1.5G spectrum and indoor LED lighting. The Shockley-Queisser (SQ) limits were estimated for LEDs with color temperatures of 3000 and 6000 K, revealing significant differences in PCE compared to standard solar radiation. The optical and electrical properties of the perovskite devices were simulated by using the transfer-matrix method and one-dimensional drift-diffusion model. We report a PCE of 15.8% for opaque devices under the AM1.5G spectrum, while the semitransparent devices exhibit PCEs of 12.07% and 10.17% for front and rear illumination, respectively. Under indoor conditions with cool LED lighting, the opaque devices demonstrate a significantly higher PCE of 28.38% and an impressive photovoltage of 1.17 V, surpassing the semitransparent devices, which show efficiencies of approximately 19.5% (front illumination) and 18.3% (rear illumination). While the interface between the hole transport layer and perovskite has a major impact on the device performance of opaque solar cells, the perovskite/electron transport layer junction plays a more critical role in the performance of semitransparent solar cells. The power densities for opaque devices reached up to 106.25 mu W/cm2 under cool LED and 97.1 mu W/cm2 with warm LED illumination. For semitransparent devices, the power densities exceeded 60.71 mu W/cm2 on front-side illumination and 73.66 mu W/cm2 on rear illumination under cool LEDs. These results emphasize the significant potential of hybrid PSCs for efficient energy harvesting under various lighting conditions, making them promising candidates for powering low-energy-consumption electronics in indoor environments.

Supported metal catalysts have attracted considerable attention because of their remarkably high catalytic activity and thermal stability. In this work, we report a facile and eco‐friendly method to synthesize porous Au/TiO ₂ nanocomposites with tunable size and different loading of Au nanoparticles. Porous TiO ₂ particles with average size of 20 nm were obtained using deep eutectic solvent‐assisted solvothermal method, in which Au NPs were immobilized by citrate reduction process. By adjusting the molar ratio of citrate and gold precursor, the size and loading of Au particles could be effectively controlled. The optimized nanocomposite with maximum Au loading and smallest particle size of 9 nm manifested the best catalytic activity in the 4‐nitrophenol reduction and excellent reusability. The superior catalytic performance can be ascribed to the strong interfacial interaction between small Au NPs and porous TiO ₂ support together with the high concentration of active sites at the interface.

Herein, we report a unique surfactant‐free synthetic pathway for the synthesis of anatase TiO ₂ catalysts in the size range of 13 to 20 nm by solvothermal method using choline chloride‐urea deep eutectic solvent (DES) as green media and 2‐propanol as cosolvent. The composition of reline was tuned by adding 0 (pure reline), 5, 10, 20 and 50 wt % of 2‐propanol. The amount of cosolvent was found to have a significant influence on TiO ₂ particle size, N ₂ isotherms and the magnitude of Urbach energy formed within the band gap of mesoporous TiO ₂ nanostructures. The sample obtained with 10 wt % of propanol showed the best photocatalytic activity in the degradation of Rhodamine B (RhB), which is attributed to the combined effect of Urbach tail states, specific surface area, particle size and band gap energy of TiO ₂ NPs. Radical trapping experiments with scavengers revealed that OH⋅ radicals are primarily responsible for RhB decomposition.