Electrochemical water splitting has emerged as a pivotal technology for green hydrogen production, offering a viable pathway toward a sustainable energy future. Among various electrolysis systems, Anion exchange membrane water electrolysis is particularly noteworthy as a cost-effective solution capable of operating under the fluctuating power inputs typical of renewable energy sources. However, the overall efficiency of water splitting is fundamentally limited by the oxygen evolution reaction, which exhibits sluggish kinetics compared to the hydrogen evolution reaction. While IrO₂ and RuO₂ serve as current benchmarks, their scarcity and high cost necessitate the development of earth-abundant alternatives. This review provides a comprehensive overview of fundamental OER mechanisms including the adsorbate evolution mechanism, lattice oxygen mechanism, and oxide path mechanism while highlighting how new pathways can circumvent traditional scaling relations. We discuss recent advancements in transition metal-based electrocatalysts, encompassing oxides, hydroxides, chalcogenides, phosphides, nitrides, and carbides, with a focus on innovative design strategies such as defect engineering, heteroatom doping, and heterostructure construction. This paper concludes by addressing current challenges and offering perspectives on future directions for the development of highly efficient and economically viable oxygen evolution electrocatalysts for large-scale applications.

Oxygen evolution reaction is a critical bottleneck for the development of efficient electrochemical hydrogen production because of its sluggish reaction. Among various catalysts, transition metal-based layered double hydroxide has drawn significant attention due to their excellent catalytic properties and cost-effectiveness. This paper begins with basic crystal structures, and then conventional adsorbate evolution mechanism of layered double hydroxide. Strategies for enhancing catalytic properties based on adsorbate evolution mechanism and lattice oxygen mechanism that could surpass theoretical limit of adsorbate evolution mechanism are discussed. This paper ends with a brief discussion on the challenges and future directions of layered double hydroxide-based oxygen evolution reaction catalysts.

As the recent climate problems are getting worse year after year, the demands for clean energy materials have highly increased in modern society. However, the candidate material classes for clean energy expand rapidly and the outcomes are too complex to be interpreted at laboratory scale (e.g., multicomponent materials). In order to overcome these issues, the firstprinciples calculations are becoming attractive in the field of material science. The calculations can be performed rapidly using virtual environments without physical limitations in a vast candidate pool, and theory can address the origin of activity through the calculations of electronic structure of materials, even if the structure of material is too complex. Therefore, in terms of the latest trends, we report academic progress related to the first-principles calculations for design of efficient electrocatalysts. The basic background for theory and specific research examples are reported together with the perspective on the design of novel materials using first-principles calculations.

Nowadays, with improvement of economical income and life qualities, life pattern changes have been brought such as increasing of avocational activities. Consequently, following those life trends, utilization of car is getting increased. Thus, the perceptions of car have been changed from the only means of transport in the past to a 2nd residental space. that is why the car`s endo environmental factors are getting so important. Air conditioner regulating air ventilization in vehicle`s indoor automatically sets the right temperature based on the differences of indoor and outdoor`s temperature with development of advanced functions to provide better environmental qualities in vehicle. However, even those advanced techniques for functional development are got so diverse though, the essential technique for preventing the growth of bateria and mold inside of the air conditioner are not even severals. Especially, evaporator one of the vehicle air conditioning equipments generates cooled air by vaporizing refrigerant in liquid state with the water as the adduct for this reactions. It has structural difficulties for water vaporation then cause the growth of germs. That`s why this reseach was focused on the way of eliminating germs in the vehicle air conditioner efficiently. Direct air sterilizer by using UVC(Ultraviolet C) is manufactured and that performances are evaluated.