 A new method has been developed to create a highly efficient catalyst for water splitting. The catalyst consists of a combination of cofee oxophosphides with a unique hierarchical hollow structure. This structure provides multiple benefits including increased surface area and improved conductivity. These features allow the catalyst to perform better than other similar catalysts in terms of efficiency and stability. This article was authored by Peng Zhang, Xue Fenglu, Jian Weini, and others.