Along with industrialization and rapid urbanization, environmental remediation is globally a perpetual concept to deliver a sustainable environment. Various organic and inorganic wastes from industries and domestic homes are released into water systems. These wastes carry contaminants with detrimental effects on the environment. Consequently, there is an urgent need for an appropriate wastewater treatment technology for the effective decontamination of our water systems. One promising approach is employing nanoparticles of metal oxides as photocatalysts for the degradation of these water pollutants. Transition metal oxides and their composites exhibit excellent photocatalytic activities and along show favorable characteristics like non-toxicity and stability that also make them useful in a wide range of applications. This study discusses some characteristics of metal oxides and briefly outlined their various applications. It focuses on the metal oxides TiO₂, ZnO, WO₃, CuO, and Cu₂O, which are the most common and recognized to be cost-effective, stable, efficient, and most of all, environmentally friendly for a sustainable approach for environmental remediation. Meanwhile, this study highlights the photocatalytic activities of these metal oxides, recent developments, challenges, and modifications made on these metal oxides to overcome their limitations and maximize their performance in the photodegradation of pollutants.

Within the framework of this study, the inductive analysis of voltage stability indices’ theoretical formulation, functionality, and overall performances are introduced. The prominence is given to investigate and compare the original indices from three main dimensions (formulation, assessment, and application) standpoints, which have been frequently used and recently attracted. The generalizability of an exhaustive investigation on comparison of voltage stability indices seems problematic due to the multiplicity of the indices, and more importantly, their variety in theoretical foundation and performances. This study purports the first-ever framework for voltage stability indices classification for power system analysis. The test results found that indices in the same category are coherent to their theoretical foundation. The paper highlights the fact that each category of the indices is functional for a particular application irrespective of the drawback ranking, and negated the application of the Jacobian matrix-based indices for online application. Finally, the research efforts put forward a novel classification of voltage stability indices within the main three aspects of formulation, assessment, and behavior analysis in a synergistic manner as an exhaustive reference for students, researchers, scholars, and practitioners related to voltage stability analysis. The simulation tools used were MATLAB^® and PowerWorld^®.

The growing global concern for climate change and the need for sustainable energy solutions have driven nations to explore renewable energy alternatives. This research focuses on a developing country heavily reliant on imported electricity and evaluates the potential of renewable energy resources. Using the Analytical Hierarchy Process (AHP), a multi-criteria decision-making method (MCDM), this study prioritizes sustainable energy resources crucial for energy security and environmental sustainability, given the country’s dependence on traditional and imported power and its potential for renewable energy development. This study employs AHP to evaluate and rank various sustainable energy options, emphasizing their technological, economic, environmental, and social impacts. The novelty of this research lies in its comprehensive and systematic approach to integrating diverse expert opinions and utilizing AHP; the development of a robust decision-making model that accommodates the diverse criteria and sub-criteria (SCs) influencing the prioritization of energy resources; and its bridging of the gaps through the integration of varied criteria and SCs, region-specific concerns, and stakeholders’ engagement by creating a comprehensive and inclusive prioritization strategy. The key findings highlight solar energy as the most viable sustainable energy resource, followed by wind and hydro energy. These results underscore the significant potential for solar energy development, considering its current technological advancements, economic affordability, social acceptance, and environmental friendliness. This study not only provides a prioritized list of sustainable energy resources but also offers a methodological framework adaptable for similar assessments in other regions facing energy transition challenges. Readers will find a detailed explanation of the AHP methodology, the criteria used for evaluating energy resources, and the implications of the findings for policy and decision making. This research is particularly relevant for policymakers, energy planners, and stakeholders interested in sustainable energy development and strategic planning in similar contexts.