Highly Crystalline Mesoporous Silicon Spheres for Efficient Visible Photocatalytic Hydrogen Evolution

High-performance and low-cost photocatalysts from earth-abundant sources are of great importance to realize large-scale hydrogen production. Silicon, a naturally abundant semiconductor with narrow bandgap, is an ideal photocatalyst due to its high solar energy utilization efficiency; however, its application in photocatalytic H-2 production is mainly limited by energy band and surface structures. Here we report the facile synthesis of highly crystalline mesoporous silicon spheres to overcome the limitations by combining salt-assisted aerosol synthesis with magnesiothermic reduction. The mesoporous silicon spheres possess high crystallinity, large specific surface area and optimal band structure, enabling efficient and stable photocatalytic H-2 evolution (1785 mu molh(-1)g(-1)) under visible light without precious metal cocatalysts. This work offers a scalable approach to highly crystalline mesoporous materials and provides new prospects in developing silicon photocatalysts for solar fuel production.