Nanoscale 2D g-C3N4 decorating 3D hierarchical architecture LDH for artificial photosynthesis and mechanism insight

• A heterojunction was constructed by nanosize 2D g-C 3 N 4 decorating 3D LDH. • A comprehensive band structure analysis by ISI-XPS and UPS was processed. • The prolonged lifetime and accelerated separation of carries was achieved. • Double mechanism driven CO 2 photoconversion process was proposed. • An enhanced CRR performance was achieved. Herein, an ACNNSLDH composite was rationally designed and successfully synthesized by decorating of 3D hierarchical architecture LDH with ultrathin nanoscale g-C 3 N 4 , which demonstrated an excellent efficiency in photoreduction of CO 2 reaction under pure H 2 O media. The well-designed heterostructure was fully confirmed by XPS, UPS, in-situ XPS characterizations, which pronouncedly resulted in prolonged lifetime and accelerated separation/transport kinetics of photo-induced carries. Supported by in-situ DRIFTS, the photoreaction process was synergistically driven by two mechanisms, we called •CO 2 − pathway and COOH* mechanism. In darkness, multiple carbonate species with activated O-C-O bonds were bound upon surface of ACNNSLDH profited from LDH, whilst ACNNS mainly played the pivotal role in light reaction process on account of the great virtue in the conversion of solar energy. The synergistic enhancement effect stimulative ability to bind and activate CO 2 molecule as well as to balance light utilization simultaneously, eventually turning out to boost the reactivity toward CO 2 .