Ozone (O₃), a strong oxidizing agent, has found widespread applications since its structure was confirmed by Schubbe in 1839. It can be produced through ultraviolet radiation, electrochemical methods, or dielectric barrier discharge (DBD), with DBD being the most efficient for large-scale production due to its high stability. Ozone is widely used in environmental management, particularly in water treatment, air pollution control, and soil remediation. In water treatment, ozone effectively removes microorganisms and contaminants without generating secondary pollutants. In air pollution control, it degrades organic compounds in industrial waste and neutralizes toxic gases in automobile exhausts. Ozone also breaks down persistent pollutants like polycyclic aromatic hydrocarbons in soil, improving soil quality. However, challenges remain related to ozone’s stability and high production costs. Beyond environmental uses, ozone is critical in industries and medicine. It helps remove pathogens and heavy metals in wastewater treatment, extends shelf life and deactivates mycotoxins in food processing, and shows promise in medical fields like orthopedics and cancer therapy. In the power industry, ozone plays a key role in water treatment and air purification. Overall, ozone technology offers significant potential for both environmental and industrial applications.

As global demand for clean energy continues to rise, hydrogen, as an ideal energy carrier, plays a crucial role in the energy transition. Traditional hydrogen production methods predominantly rely on fossil fuels, leading to environmental pollution and energy inefficiency. In contrast, plasma-assisted hydrogen production, as an emerging technology, has gained significant attention due to its high efficiency, environmental friendliness, and flexibility. Plasma technology generates high-energy electrons or ions by exciting gas molecules, which, under specific conditions, effectively decompose water vapor or hydrocarbon gases to produce hydrogen. This review systematically summarizes the basic principles, technological routes, research progress, and potential applications of plasma-assisted hydrogen production. It focuses on various plasma-based hydrogen production methods, such as water vapor decomposition, hydrocarbon cracking, arc discharge, and microwave discharge, highlighting their advantages and challenges. Additionally, it addresses key issues facing plasma-assisted hydrogen production, including energy efficiency improvement, reactor stability, and cost optimization, and discusses the future prospects of these technologies. With ongoing advancements, plasma-assisted hydrogen production is expected to become a mainstream technology for hydrogen production, contributing to global goals of zero carbon emissions and sustainable energy development.

The sulfur-iodine (SI) cycle holds great promise as an alternative large-scale process for converting water into hydrogen without CO₂ emissions. A major issue regarding the long-term stability and activity of the catalysts is their poor sulfur deactivation resistance in the HI feeding process. In this work, the effect of Ru addition for enhancing the activity and sulfur resistance of SiO₂-supported Ni catalysts in the HI decomposition reaction has been investigated. The presence of H₂SO₄ molecules in the HI results in severe sulfur deactivation of the Ru-free Ni/SiO₂ catalysts by blocking the active sites. However, Ni–Ru/SiO₂ catalysts show higher catalytic activity without sulfur-poisoning by 25% and exhibit more superior catalytic performance than the Ru-free catalyst. The addition of Ru to the Ni/SiO₂ catalyst promotes the stability and activity of the catalysts. The experimental trends in activity and sulfur tolerance are consistent with the theoretical modeling, with the catalytic activities existing in the order Ni/SiO₂ < Ni–Ru/SiO₂. The effect of Ru on the improvement in sulfur resistance over Ni-based catalysts is attributed to electronic factors, as evidenced by theory modeling analysis and detailed characterizations.