Near‐Field Drives Long‐Lived Shallow Trapping of Polymeric C₃N₄ for Efficient Photocatalytic Hydrogen Evolution

Abstract

Undesired photoelectronic dormancy through active species decay is adverse to photoactivity enhancement. An insufficient extrinsic driving force leads to ultrafast deep charge trapping and photoactive species depopulation in carbon nitride (g-C 3 N 4 ). Excitation of shallow trapping in g-C 3 N 4 with longlived excited states opens up the possibility of pursuing high-efficiency photocatalysis. Herein, a near-field-assisted model is constructed consisting of an In 2 O 3 -cube/g-C 3 N 4 heterojunction associated with ultrafast photodynamic coupling. This In 2 O 3 -cube-induced near-field assistance system provides catalytic "hot areas", efficiently enhances the lifetimes of excited states and shallow trapping in g-C 3 N 4 and this favors an increased active species density. Optical simulations combined with time-resolved transient absorption spectroscopy shows there is a built-in charge transfer and the active species lifetimes are longer in the In 2 O 3 -cube/g-C 3 N 4 hybrid. Besides these properties, the estimated overpotential and interfacial kinetics of the In 2 O 3 -cube/g-C 3 N 4 hybrid co-promotes the liquid phase reaction and also helps in boosting the photocatalytic performance. The photocatalytic results exhibit a tremendous improvement (34-fold) for visible-light-driven hydrogen production. Near-fieldassisted long-lived active species and the influences of trap states is a novel finding for enhancing (g-C 3 N 4 )-based photocatalytic performance.

Polarization Engineering of Covalent Triazine Frameworks for Highly Efficient Photosynthesis of Hydrogen Peroxide from Molecular Oxygen and Water

“…Therefore, to achieve highly active and selective photosynthesis of H 2 O 2 from H 2 O and O 2 , both the ORR for H 2 O 2 production and 4e − WOR should occur simultaneously, which requires rational designs of CTFs with decreased bulk-recombination rates. [17][18][19] To address the poor efficiency of charge separation-induced low photocatalytic activity, several strategies such as p-n junction, heteroatom doping, and defect engineering have been proposed in polymer photocatalysts system. [20][21][22][23][24][25] The engineering of functional groups is a promising route to radically change the inherently fast bulk-recombination rates of polymer semiconductors, endowing them with unique electrical and optical properties at molecular level.…”

One‐Step MOF‐Templated Strategy to Fabrication of Ce‐Doped ZnIn2S4 Tetrakaidecahedron Hollow Nanocages as an Efficient Photocatalyst for Hydrogen Evolution

“…[ 44 , 45 ] As shown in Figure 7d , the photocurrent of ZTNs‐Ce20 is much higher than that of ZIS, implying that the ZTNs‐Ce20 nanocages enhance charge transfer at the interface while suppressing the recombination rate of photogenerated electrons and holes. [ 10 , 46 ]…”

“…[44,45] As shown in Figure 7d, the photocurrent of ZTNs-Ce20 is much higher than that of ZIS, implying that the ZTNs-Ce20 nanocages enhance charge transfer at the interface while suppressing the recombination rate of photogenerated electrons and holes. [10,46] The light-harvesting capability of ZIS and ZTNs-Cex (x = 10, 15, 20, 30, 40, 60) was examined by UV-vis diffuse reflectance spectra (UV-vis DRS). As shown in Figure S11a (Supporting Information), ZIS shows a visible absorption edge at ≈480 nm, and after Ce doping, the absorption edge shows a significant redshift, indicating that Ce has been doped into the crystal structure of ZIS.…”

The Influence of Metal-Doped Graphitic Carbon Nitride on Photocatalytic Conversion of Acetic Acid to Carbon Dioxide

“…Hence, trapped shallow electrons considerably improve photocatalytic activity. In the case of the deep trapped state, these electrons are easily recombined, which leads to poor photocatalytic activity ( Choudhury et al, 2014 ; Ruan et al, 2020 ; Wang et al, 2021 ). However, the photocatalytic behavior of Cu_CN cannot be explained by this hypothesis.…”