Three-dimensionally ordered Macroporous perovskite sodium tantalum for robust hydrogen and hydrogen peroxide production

Constructing photocatalytic materials into three-dimensionally ordered macroporous (3DOM) is considered an effective strategy for improving mass transfer behaviors and shortening the electron migration path. However, this strategy is challenging for ternary semiconductors because they cannot be directly synthesized by traditional thermal decomposition methods. Ternary systems need to face the structural instability caused by the construction of macroporous morphology, which limits the application of the ordered macroporous structure. In this work, we designed a novel and efficient two-step crystal nucleation strategy for constructing a highly stable ternary ordered macroporous structure. Here, 3DOM NaTaO3 was reported as a promising candidate. Compared with nonporous NaTaO3, which has no catalytic activity in pure water, 807.9 and 280.1 μmol g-1h-1 of H2 and H2O2 production rates were first achieved on the 3DOM NaTaO3. Furthermore, the rate of photocatalytic H2 evolution over the 3DOM NaTaO3 improved sharply to 3.9 mmol g-1h-1 in methanol aqueous solution, which was 139 times that of nonporous NaTaO3. The construction of 3DOM NaTaO3 enables the participation of the bulk interior in photochemical reaction and provides more options for later decoration. This work opens a new door for constructing more 3DOM ternary semiconductors for catalytic reactions.