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We present high-yield hydrogen production through selective photocatalytic decomposition of formic acid by using electrospun TiO 2 nanofibers decorated with AuPd bimetallic alloy nanoparticles under simulated sunlight irradiation. By using only 5 mg of the AuPd/TiO 2 nanofibers containing the 0.75% Au and 0.25% Pd, we could achieve an optimal H 2 generation rate of 88.5 μmol h −1 with an apparent quantum yield at 365 nm as 15.6%, which is higher than that of the Pd/TiO 2 and Au/TiO 2 nanofibers by a factor of 1.6 and 4.5, respectively. The enhanced photocatalytic decomposition of formic acid for H 2 generation could be attributed to the stronger electron-sink effect of AuPd alloy nanoparticles, the high selectivity of Pd for the dehydrogenation of formic acid, and the surface plasmon resonance effect of Au. More importantly, we demonstrate that the photocatalytic processes enable re-activation of the AuPd nanoparticles that were poisoned by CO during thermal decomposition of formic acid. As such, the presented AuPd/TiO 2 nanofibers are promising materials for re-generation of H 2 under mild conditions from liquid storage carrier of hydrogen. [ABSTRACT FROM AUTHOR]

• 2D multi-hetero-interface was constructed in Ti 3 C 2 T x /(001)TiO 2 /C 3 N 4 nanosheets. • Ti 3 C 2 T x /(001)TiO 2 /C 3 N 4 nanosheets were produced by the in-situ oxidation/electrostatic self-assembly strategy. • Broad electron-transfer channels in the 2D multi-hetero-interface enhance the charge separation and utilization. • Photocatalytic activities of H 2 generation and CO 2 reduction were remarkably enhanced. The hetero-interface quality and area in the semiconductor heterostructure are important to the photocatalytic performance of the heterostructure. The 2D hetero-interface between two 2D semiconductors has been widely proved to enhance the photocatalytic performance, because the larger contact area of the hetero-interface can effectively improve the charge separation behavior. However, engineering high-quality 2D multi-hetero-interface in the well-designed semiconductor composite to further enhance the charge separation and utilization is still a big challenge. Herein, we constructed the 2D multi-hetero-interface in the well-designed nanosheet (NS) composite photocatalyst through an in-situ oxidation treatment combined with the electrostatic self-assembly strategy. The negatively-charged binary Ti 3 C 2 T x /(001)TiO 2 heterojunction NSs with the intimate 2D contact interface was fabricated through a facile in-situ oxidation method, while the protonated g-C 3 N 4 NSs were positively charged. Thus, the spontaneous electrostatic attraction behavior between the above opposite-charged materials of the Ti 3 C 2 T x /(001)TiO 2 heterojunction and the g-C 3 N 4 NSs enables the 2D multi-hetero-interface to be constructed in the Ti 3 C 2 T x /(001)TiO 2 /C 3 N 4 NSs. As such, the 2D multi-hetero-interface offers broad electron-transfer channels to enhance the charge separation and utilization. Upon simulated sunlight irradiation, the optimal Ti 3 C 2 T x /(001)TiO 2 /C 3 N 4 NSs achieved about 4-fold enhancement on the photocatalytic H 2 generation and 3-fold improvement on the photocatalytic CO 2 reduction as compared to the pure (001)TiO 2 or g-C 3 N 4 NSs. [ABSTRACT FROM AUTHOR]