Optimizing Electronic Density at Active W Sites for Boosting Photocatalytic H₂ Evolution

Abstract

It is highly desirable but challenging to optimize the electronic structure of an active site to realize moderate active site-H ads bond energies for boosting photocatalytic H 2 evolution. Herein, an interfacial engineering strategy is developed to simultaneously concentrate hydrogen species and accelerate the combination of an H ads intermediate to generate free H 2 by constructing W−WC− W 2 C (WCC) cocatalysts. Systematic investigations reveal that hybridizing with W 2 C creates electron-rich W active sites and effectively induces the downshift of the dband center of W in WC. Consequently, the strong W−H ads bonds on the surface of WC are weakened, thus promoting the desorption of H ads to rapidly produce free H 2 . The optimized 40-WCC/CdS photocatalyst exhibits a high hydrogen evolution rate of 63.6 mmol g −1 h −1 under visible light (≥420 nm) with an apparent quantum efficiency of 39.5% at 425 nm monochromatic light, which is about 40-fold of the pristine CdS. This work offers insights into the design of cocatalyst for highefficiency photocatalytic H 2 production.

Rational Design of Z-Scheme Heterostructures Composed of Bi/Fe-Based MOFs for the Efficient Photocatalytic Degradation of Organic Pollutants

“…According to the outcomes mentioned above, CM-2 exhibits the least intensity of PL emission, indicating its remarkable capability to effectively segregate photogenerated carriers [38]. As depicted in Figure 6e, a comparison was made between the transient photocurrent response of CAU-17 without impurities, MIL-100(Fe), and CM-2.…”

Construction of Reverse Type-II InP/ZnxCd1–xS Core/Shell Quantum Dots with Low Interface Strain to Enhance Photocatalytic Hydrogen Evolution

“…Hydrogen is considered as an ideal energy carrier for replacing traditional fossil fuels due to its high specific enthalpy of combustion and pollution-free combustion product. − And converting solar energy into chemical energy through photocatalytic reactions and storing it in the form of H 2 are regarded as one of the most effective solutions for addressing current energy problems. − Colloidal semiconductor nanocrystals, also known as quantum dots (QDs) with a much smaller size than their exciton Bohr radius, have garnered considerable attention in the realm of photocatalytic H 2 evolution . Compared to bulk semiconductors, the band gap of QDs could be tuned by adjusting their size, and the extremely small size also facilitates the exciton transfer toward the surface, thereby promoting rapid charge separation and the subsequent redox reaction. , Therefore, owing to their high light absorption coefficient, superior light harvesting capacity, large specific surface area, and abundant active sites, the photocatalytic H 2 evolution reactions based on QDs have been extensively reported in recent years.…”