In the context of the shipping industry emission reduction target set by the International Maritime Organization and based on the current situation of carbon reduction in the shipping industry, this paper introduces the development history and emission reduction advantages of hydrogen powered ships, analyzes the hydrogen storage methods of hydrogen powered ships at home and abroad and the safety risks of hydrogen energy onboard, and compares the technical advantages and onboard feasibility of various Marine hydrogen storage methods. It is concluded that the hydrogen production technology of shipboard methanol steam reforming is of great significance to solve the hydrogen safety problem of hydrogen?powered ships. At last, the problems faced in developing hydrogen?powered ships with shipboard hydrogen production units are put forward.

Ozone is a clean and strong oxidant, which has been widely used in the degrading of organic pollutants. However, the ozone oxidation process alone is not ideal for the treatment of difficult?to?degrade organic pollutants in water. Therefore, ozone catalytic oxidation technology came into being, and the selection of catalyst is the key factor to determine its degradation effect. Based on the various types of catalysts, the mechanism of metal oxides, carbon?based materials and supported composite catalysts for the catalytic oxidation treatment of water pollutants by ozone was reviewed. The existing problems and the main problems that need to be solved at present were analyzed to provide theoretical basis and reference for the research and development of suitable catalysts.

As an important semiconductor photocatalytic material, bismuth oxide (Bi₂O₃) is considered as a promising visible photocatalyst due to its special electronic structure and excellent visible light response performance. It displays a good application prospect in photocatalytic treatment of wastewater. However, the application of Bi₂O₃ is limited by its low photocatalytic performance, therefore, Bi₂O₃ pholocatalyst with superior performance is expected to be obtained by modifying methods by the researchers. In this review, a series of modification methods, such as surface morphology regulation, surface modification, metal ion modification and semiconductor combination, are summarized. Then, the future development of modified Bi₂O₃ photocatalytic materials is prospected.