Triple-Channel Charge Transfer over W₁₈O₄₉/Au/g-C₃N₄ Z-Scheme Photocatalysts for Achieving Broad-Spectrum Solar Hydrogen Production

Abstract

Z-scheme heterojunctions are fundamentally promising yet practically appealing for photocatalytic hydrogen (H2) production owing to the enhanced redox power, spatial separation of charge carriers, and broad-spectrum solar light harvesting. The charge-transfer dynamics at Z-scheme heterojunctions can be accelerated by inserting charge-transfer mediators at the heterojunction interfaces. In this study, we introduce Au nanoparticle mediators in the Z-scheme W18O49/g-C3N4 heterostructure, which enables an improved H2 production rate of 3465 μmol/g·h compared with the direct Z-scheme W18O49/g-C3N4 (1785 μmol/g·h) under 1 sun irradiation. The apparent quantum yields of H2 production with W18O49/Au/g-C3N4 are 3.9% and 9.3% at 420 and 1200 nm, respectively. The improved photocatalytic H2 production activity of W18O49/Au/g-C3N4 is attributable to the triple-channel charge-transfer mechanism: channel IZ-scheme charge transfer facilitates charge separation and increased redox power of the photoexcited electrons; channels II and IIIthe localized surface plasmon resonances from Au (channel II) and W18O49 (channel III) enable light harvesting extension from visible to near-infrared wavelengths.

Constructing asymmetric active sites on defective Ru/W18O49for photocatalytic nitrogen fixation

“…More importantly, an additional absorption is observed on Ru/W 18 O 49 , ranging from 500 nm to 800 nm, which is due to the LSPR effect between Ru and defective W 18 O 49 via plasmon hybridization. 23,27,32 Thus, the localized electrons within defect states on W 18 O 49 may transfer to Ru via the LSPR effect, further accelerating the N 2 activation on Ru/W 18 O 49 for efficient ammonia synthesis.…”

Metallic WN plasmonic fabricated g-C3N4 significantly steered photocatalytic hydrogen evolution under visible and near-infrared light

“…5a, it is evident that the PL intensity of all WN/CN- x photocatalysts decreases markedly with increasing content of plasmonic WN NPs in comparison with that of pure g-C 3 N 4 , suggesting the effective charge transfer of photoinduced electrons from the plasmonic WN NPs to g-C 3 N 4 , which in turn is exceptionally advantageous for inhibiting electron–hole recombination. 45 Furthermore, to explore the lifetime period of photoinduced electron–hole pairs and their migration and separation efficiency, time-resolved photoluminescence (TRPL) spectra were recorded. Fig.…”

Construction and excellent photoelectric synergistic anticorrosion performance of Z-scheme carbon nitride/tungsten oxide heterojunctions

“…The W 18 O 49 semiconductor because of the localized surface plasmon resonance (LSPR) effect given by OVs can cause full spectrum absorption of sunlight, significantly increasing the electron density. 22,23 Although the exposed surface oxygen vacancy defects are unstable and induce rapid compounding of photogenerated carriers in deep trap states, 24 their interfacial interactions in heterojunction structures can achieve defect passivation. 25,26 Therefore, W 18 O 49 is very suitable for coupling with g-C 3 N 4 to design Z-scheme heterojunctions.…”