Rationally Designed Double‐Shell Dodecahedral Microreactors with Efficient Photoelectron Transfer: N‐Doped‐C‐Encapsulated Ultrafine In2O3 Nanoparticles

Abstract It is desirable but challenging to design efficient micro‐/nanoreactors for chemical reactions. In this study, we have fabricated mesoporous double‐shelled hollow microreactors composed of N‐doped‐C‐coated ultrafine In 2 O 3 nanoparticles [N‐C/In 2 O 3 HD (hollow dodecahedron)] by the thermolysis of a dodecahedral In‐based framework in Ar atmosphere. The obtained N‐C/In 2 O 3 HD exhibited excellent activity in the photocatalytic oxidative hydroxylation of a series of arylboronic acid substrates. This property can be attributed to its enhanced optical absorption and efficient separation of photo‐generated electron–hole pairs, imparted by the unique structure and uniformly coated N‐doped C layers. Furthermore, we found O 2 .− to be the critical active species in the process of photocatalytic oxidative hydroxylation of arylboronic acids, and the formation mechanism of this radical is also proposed. Theoretical calculations further confirmed that the N‐doped C layer serves as an electron acceptor and revealed the microscopic charge‐carrier migration path through the In 2 O 3 /N‐doped graphite interfaces. Thus, photo‐generated electrons from hybrid states of In 2 O 3 , composed of In 5s and 2p orbitals, are transferred into the hybrid states of N‐doped graphite, composed of C 2p and N 2p orbitals. The present study may be helpful for understanding and designing carbon‐based micro‐/nanoreactors for photocatalytic reactions, and may also be useful for investigating related micro‐/nanoreactors.