we provide a mesoporous silicon material prepared via a template - free and hf - free process . the production process is facile and scalable , and it may be conducted under mild reaction conditions . the silicon may be produced directly by the reduction of a silicon - halogenide precursor with an alkaline alloy . the resulting si - salt matrix is then annealed for the pore formation and crystallite growth . final product is obtained by removal of the salt by - products with water .