Boosting Charge Carrier Separation by Constructing a Dual Metal–Organic Framework-Derived CuO@TiO₂ Heterojunction toward Efficient Visible-Light-Driven Hydrogen Production

Abstract

The development of photocorrosion-resistant, recoverable, and stable photocatalysts for high-efficiency visible light photocatalytic production of hydrogen is a very urgent task. Herein, a strategy to fabricate CuO@TiO 2 heterojunction photocatalysts (CuTi-X) by calcining a dual metal−organic framework at different temperatures has been reported. The results reveal that the CuTi-X catalysts have a regular morphology, highly porous structure, and large specific surface area, providing more contact sites for surface mass transfer in photocatalytic reactions. The TiO 2 component is in close contact with the CuO layer uniformly supported on the surface, which facilitates the migration and separation of photogenerated carriers. Optical and electrochemical analyses further confirm that the optimized CuO@TiO 2 (CuTi-450) heterojunction exhibits an extended photogenerated carrier lifetime and a reduced mass transfer resistance. CuTi-450 shows a photocatalytic hydrogen evolution rate under visible light irradiation of 1458.1 μmol g −1 h −1 , which is 36.2 and 5.5 times higher than that of the single TiO 2 (Ti-450) and CuO (Cu-450) components, respectively, and remains stable after four reaction cycles. This work opens an avenue to design stable and efficient oxide heterojunction photocatalysts derived from dual MOFs.

Metal–Organic Framework-Derived Hierarchical Ag/Sr6Bi2O9-α-Bi2O3 Ternary Photocatalyst for Micropollutant Remediation and Bacterial Photoinactivation

“…In addition, MOFs have been used as a sacrificial template for fabrication of high-surface-area and porous metal oxides, which are otherwise rarely achieved through conventional synthesis routes. For example, metal oxide semiconductors including Co 3 O 4 , In 2 O 3 , ZnO, Cu 2 O-CeO 2 , and CuO@TiO 2 with enhanced photocatalytic activity have been synthesized by using mono and bimetallic MOFs as sacrificial agents. − Although there are studies on the synthesis of MOF-derived metal oxides, a very few of them deal with the preparation of high-surface-area bismuth-based oxides using the Bi-MOF as a precursor . Moreover, there is no report on one-pot fabrication of oxide–oxide heterojunctions involving Bi 2 O 3 as a photoactive component by using the MOF-derived route.…”

Two Cu(i) coordination polymers based on a new benzimidazolyl-tetrazolyl heterotopic ligand for visible-light-driven photocatalytic dye degradation

“…20,21 Recently, much attention has been given to the use of coordination polymers as visible-light-driven photocatalysts, mainly because their electronic structure can be easily regulated by metal ions and ligands. [22][23][24][25][26][27][28] Previous reports indicate that copper-based CPs usually have rich photophysical properties and exhibit photocatalytic functions towards organic and inorganic contaminants. [29][30][31][32][33] Inspired by this and our continuous studies on heterotopic triangular ligands, 15,16,[34][35][36]…”

Efficient Visible-Light Photocatalytic Hydrogen Evolution over the In2O3@Ni2P Heterojunction of an In-Based Metal–Organic Framework

“…In this context, the conversion of sunlight into clean and renewable hydrogen (H 2 ) energy via photocatalytic water splitting has gained traction . However, the photocatalysts used in this conversion process are commonly constrained by the low redox potential or a rapid electron–hole recombination rate . On this occasion, the construction of a heterojunction by matching the arrangement of two energy levels via interface engineering is a hopeful route to achieve high charge separation efficiency and a desirable redox potential .…”

“…2 However, the photocatalysts used in this conversion process are commonly constrained by the low redox potential or a rapid electron−hole recombination rate. 3 On this occasion, the construction of a heterojunction by matching the arrangement of two energy levels via interface engineering is a hopeful route to achieve high charge separation efficiency and a desirable redox potential. 4 Compared with the conventional type-I heterojunction, the construction of a type-II heterojunction offers a faster spatial charge separation rate, making it one of the most widely used types of heterojunctions for boosting the performance of photocatalysts.…”