High yield regeneration of 1,4-NAD(P)H via selective adsorption-/desorption-mediated visible-light photocatalysis on a noble-metal-free catalyst

Abstract

A type II Bi₁₂O₁₇Cl₂–Bi₄₈Al₂O₇₅ heterojunction in Al₂O₃ support, named Bi₁₂O₁₇Cl₂–Bi₄₈Al₂O₇₅–Al₂O₃, was synthesized in a one-pot process as a visible-light photocatalyst for the high-yield regeneration of 1,4-NAD(P)H. Owing to its superior photocarrier separation capability and rapid adsorption of NAD(P)⁺ (but negligible adsorption of NAD(P)H), the proposed photocatalyst achieved effective regeneration of 1,4-NAD(P)H without the need for additional noble-metal mediators. An 89% NADH yield with 77% selectivity for 1,4-NADH and a 92% NADPH yield with 80% selectivity for 1,4-NADPH were achieved when triethanolamine was used as the sacrificial agent. In addition, the simultaneous regeneration of NADH and oxidation of benzylamine to N-benzylbenzaldimine was also successful, yielding 67% NADH with 57% selectivity for 1,4-NADH and 17% N-benzylbenzaldimine. This work not only offers a novel noble-metal-free photocatalyst for achieving the highest yield of 1,4-NAD(P)H but also provides an innovative strategy for designing and preparing a novel type II heterojunction in the Al₂O₃ support.