The Polyacrylonitrile (PAN)/g-C3N4/CdS nanofiber sono-photocatalysts were successfully synthesized by an ordinary electrospining-chemical deposition method. The PAN/g-C3N4/CdS heterojunction nanofibers constructed with the CdS nanoparticles deposited on the PAN/g-C3N4nanofibers. The g-C3N4/CdS heterojunction increase of light absorption and the construction of heterojunction can depress recombination of charge carrier and PAN nanofibers improve the recyclability successfully. Finally, a highly effective photocatalytic activity was performed by degradation of Rhodamine B (RhB) in visible light irradiation. Furthermore, an ultrasonic method is introduced into the sono-photocatalytic system to enhance the degradation efficiency of RhB ascribed to the synergistic effect of ultrasound.Keywords:PAN/g-C3N4/CdS heterojunction;low power ultrasound;sono-photocatalytic activity;nanofibers
Zihan Yang,Jingkai Yang,Lixia Li,Wanning Cao,Jiao Zhang,Hongli Zhao,Liqin Wang
The challenge of creating effective S-scheme visible-light photocatalysts persists due to the inactive visible-light-driven component and the low band-gap characteristics of semiconductors. In this work, we developed a novel F-BiVO 4 /g-C 3 N 4 /CdS dual S-scheme photocatalyst using a sonochemical method. The removal efficiency of Cr(VI) and ciprofloxacin (CIP) can reach 98 % and 90 % in 5 min and 30 min, respectively, under simulated solar illumination. The excellent photocatalytic activity can be attributed to the efficient carrier separation and transport with the help of internal electric field at the interface. This work also reveals the reduction process of Cr(VI), as well as the intermediates and pathways involved in the CIP degradation, taking into account practical situations and expanding its potential applications. This research presents promising prospects for the design of bismuth-based dual S-scheme heterojunctions in the field of environmental remediation.
Herein we first coupled a wide photo-response photocatalyst with plasmon-enhanced triplet − triplet annihilation upconversion (TTA-UC) nanoparticles for photocatalytic hydrogen generation. The plasmon-based enhancement of TTA-UC was achieved by introducing Au nanoparticles into the core liquid of TTA-UC nanoparticles containing platinum(II)-octaethylporphyrin and 9,10-diphenylanthracene. Au-TTA nanoparticles encapsulated by silica shells significantly increased the green-to-blue upconversion compared with TTA nanoparticles. The silica shells after further surface functionalization can conjoin with photocatalysts. To improve the stability of cadmium sulfide (CdS), graphitic carbon nitride (g-C 3 N 4 ) was combined with CdS for g-C 3 N 4 -CdS heterojunctions. g-C 3 N 4 -CdS sheets based on Au-enhanced TTA-UC can utilize the upconverted high-energy photons and thereby realized efficient photocatalytic hydrogen production. Au-TTA nanoparticles conjoined with g-C 3 N 4 -CdS reached a high hydrogen production of 16.88 mmol g −1 under visible-light irradiation and an apparent quantum efficiency of 1.439% under green-light irradiation. The study provides a new TTA-supported upconversion-photocatalysis system enhanced by Au plasmon resonance effect for effectively hydrogen generation.
In this study, a self-biased bio-photoelectrochemical system (SB-BPES) was constructed using a bioanode and the g-C 3 N 4 /CdS heterojunction photocathode for nitrofurazone (NFZ) degradation under solar irradiation. The physio-chemical properties and optical performance of photocatalysts were characterized, and photo-electrochemical properties of various photocathodes were analyzed. Results showed that g-C 3 N 4 /CdS exhibited the broadest visible light absorption range (to 594 nm) and the most efficient e − -h + separation; and its corresponding photocathode showed the highest photocurrent (9.8 μA), and the lowest charge transfer resistance (5.43 ☓ 10 3 Ω). In the solar-illuminated SB-BPES with g-C 3 N 4 /CdS photocathode, about 80% of NFZ removal rate was achieved within 10 h. More importantly, TOC removal of 62.6% was achieved in 24 h, which was 1.8 times of that from the open circuit SB-BPES, and 4.3 folds of that from microbial degradation; also, about 1.5 times of those from SB-BPES with g-C 3 N 4 and CdS photocathodes. Besides, reproducible current generations (∼1.0 mA) were produced. These verified that it was a self-sustained system for spontaneously pollutants degradation and electricity generation. Moreover, possible degradation mechanism and pathways were proposed according to the identified intermediates. This study provides inspiration for synchronic improving refractory organics degradation and net energy recovery.
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