Stable d¹⁰ Metal–Organic Framework Exhibiting Bifunctional Properties of Photocatalytic Hydrogen and Oxygen Evolution

Abstract

A d 10 metal−organic framework ([Hg(Bpbp)(SCN) 2 ] n (CQNU-1, Bpbp = 4,4′-bis(4-pyridyl)biphenyl) has been synthesized and evaluated as a photocatalyst for water splitting. UV−vis spectra and Mott−Schottky analysis indicate that CQNU-1 is a potential photocatalyst with dual functions of hydrogen and oxygen evolution. The results of photocatalytic reactions over CQNU-1 show that, in the presence of a sacrificial agent, the average H 2 and O 2 evolution rates obtained by the pristine CQNU-1 are ∼7.0 and ∼3.4 μmol h −1 during a 9 h test with three cycles, respectively.

Solar-Driven Gas-Phase Moisture to Hydrogen with Zero Bias

“…Current light-driven water splitting methods are usually based on semiconductors for water oxidation or reduction. , For an integrated PEC device, the position of the valence band and conduction band should match well with the potential of water splitting . For water oxidation, the valence band position should be near 2 eV, while for water reduction, the conduction band position must be more negative than the water reduction potential. , To this end, engineering the band structure of the heterojunctions offers an excellent strategy to manipulate the charge separation and transfer . The charges will redistribute at a heterojunction’s interface due to the differences in their surface work function. , If the work function of the outer layer is larger than that of the semiconductor in contact, electrons will flow from the inside to outside until an equilibrium is attained, causing an upward band bending for the inner semiconductor.…”

“…18 For water oxidation, the valence band position should be near 2 eV, while for water reduction, the conduction band position must be more negative than the water reduction potential. 19,20 To this end, engineering the band structure of the heterojunctions offers an excellent strategy to manipulate the charge separation and transfer. 19 The charges will redistribute at a heterojunction's interface due to the differences in their surface work function.…”

Transition Metal Ion‐Directed Coordination Polymers with Mixed Ligands: Synthesis, Structure, and Photocatalytic Activity for Hydrogen Production and Rhodamine B Degradation

“…Coordination polymers (CPs) constructed from rigid organic connectors and earth‐abundant metal ions or metal clusters have exhibited excellent photocatalytic activity on the hydrogen evolution and waste water treatment under UV, visible, and/or sunlight irradiations. [ 5,6 ] By optimizing the chromophoric backbone of the organic ligands or adopting cheap metal sources, lots of earth‐abundant Cu I/II ‐, Co II ‐, Ni II ‐, Cd II ‐, and Hg II ‐based CPs with well‐tunable structural abundance and energy band structures have been rationally designed and successfully fabricated, [ 7–11 ] which have improved greatly the hydrogen evolution rate up to 26.1 mmol · g –1 · h –1 and degradation percentage of organic dyes up to 99 % in a very short time. [ 12 ] These enhanced activity benefits essentially from their well‐tailorable semiconductive nature, favorable microporous structures, and strengthened light‐harvesting ability.…”