New device splits water for green hydrogen fuel using only solar energy

Scientists at the Centre for Nano and Soft Matter Sciences (CeNS) in Bengaluru, India, have developed a scalable, next-generation device that produces green hydrogen by splitting water molecules using only solar energy. This innovative system relies solely on earth-abundant materials and solar power, eliminating the need for fossil fuels or expensive resources. The device features a silicon-based photoanode with an n-i-p heterojunction architecture composed of stacked n-type TiO2, intrinsic silicon, and p-type NiO semiconductor layers. These layers enhance charge separation and transport, improving light absorption and reducing recombination losses, which are critical for efficient solar-to-hydrogen conversion. The device demonstrated a surface photovoltage of 600 mV, a low onset potential of about 0.11 VRHE, and maintained long-term stability over 10 hours with minimal performance degradation. This advancement promises high efficiency, durability, and cost-effectiveness, with potential for large-scale production using industry-ready magnetron sputtering techniques.