Yellow hydrogen, also referred to as photochemical hydrogen, is a revolutionary form of hydrogen produced through a water separation photocatalysis process powered by solar energy and engineered catalysts. This innovative approach sets it apart from traditional hydrogen production methods like green or blue hydrogen, as it does not rely on fossil fuels and does not contribute to greenhouse gas emissions. The production process involves using semiconductor photocatalysts to split water into hydrogen and oxygen, with hydrogen being stored for various applications while oxygen is released into the atmosphere. Yellow hydrogen offers numerous advantages, including its environmentally friendly nature, high energy conversion efficiency of up to 19%, potential for decentralized production, and utilization of affordable materials. However, challenges such as limited operating time, expensive photocatalysts, and lower production rates compared to existing methods still need to be addressed through ongoing research and development. Research institutions like the National Renewable Energy Laboratory and universities such as UC Berkeley and University of Colorado Boulder are actively engaged in advancing yellow hydrogen technology. States like California, Texas, Arizona, and New Mexico are seen as promising regions for yellow hydrogen development due to their solar resources and existing energy infrastructure. Despite the progress made, further optimization and research are necessary to enhance the efficiency and practicality of yellow hydrogen production. Continued efforts in artificial photosynthesis and material development aim to overcome current limitations and establish yellow hydrogen as a competitive and sustainable energy source for the future.