Boosting Photocatalytic <scp> H <sub>2</sub> O <sub>2</sub> </scp> Synthesis Over <scp>HKUST</scp> ‐1 <scp>MOFs</scp> ‐Derived Hollow <scp>HKUST</scp> ‐1@ <scp>CuFePBA</scp> @ <scp>CuS</scp> Heterojunctions
Xiao Wen Mu, Xiaofeng Sun, Zao Yi, Shifa Wang, Babak Kakavandi, Guorong Liu, H. Yang
Abstract
Recently, photocatalytic synthesis of H 2 O 2 has received much attention. However, the photocatalytic activity of photocatalysts is generally limited due to multiple factors, such as insufficiency of photoelectrons, low adsorption capability of O 2 on the photocatalyst surface, and high thermodynamic barrier. To address these issues, herein we have designed an interesting kind of hollow HKUST‐1@CuFePBA@CuS (HS@CuFe@CuS) heterojunction photocatalyst. HKUST‐1 metal–organic frameworks (MOFs) with cubic morphology were first synthesized as the precursor. Next, Cu 2+ ions were released from HKUST‐1 for the growth of CuFe Prussian blue analogue (CuFePBA) nanosheets on the HKUST‐1 surface and then CuS nanoparticles on the CuFePBA nanosheet surface, simultaneously creating a hollow structure in HKUST‐1. It is demonstrated that the resultant photocatalysts exhibit remarkable photocatalytic activity for H 2 O 2 synthesis. Particularly, the H 2 O 2 yield rate reaches 927 μmol g −1 h −1 over the HS@CuFe@CuS‐4, which is increased by 5.3, 10.3, and 5.2 times as compared with that over single HKUST‐1, CuFePBA, and CuS, respectively. Experimental and theoretical studies outline several advantages of the hollow HS@CuFe@CuS heterostructures for boosting the photocatalytic H 2 O 2 synthesis: 1) more photoelectrons available for O 2 photoreduction reactions due to the efficient photocarrier separation/transfer and unique hollow structure, 2) increased O 2 adsorption on the active sites, and 3) a decrease in the Gibbs free energies for O 2 photoreduction reactions. This study highlights a promising nanostructure design strategy of photocatalysts for boosting H 2 O 2 synthesis.