Doping-induced enhancement of crystallinity in polymeric carbon nitride nanosheets to improve their visible-light photocatalytic activity

Li, Yuanyuan; Zhou, Bing‐Xin; Zhang, Hua-Wei; Ma, Shao-Fang; Huang, Wei‐Qing; Peng, Wei; Hu, Wangyu; Huang, Gui‐Fang

doi:10.1039/c9nr00229d

Cited by 136 publications

(55 citation statements)

References 65 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Based on the previous reports, the crystallinity of the photocatalysts would significantly affect the photocatalytic HER. To some extent, the high crystallinity layer would result in better photocatalytic HER 59,60 . Additionally, the peaks of MCS show a little shift after loading MXene, especially for the angles of MCS/0.3 MXene and MCS/0.5 MXene.…”

Section: The Structure and Morphologymentioning

confidence: 99%

Constructing 1D/2D Schottky-Based Heterojunctions between Mn0.2Cd0.8S Nanorods and Ti3C2 Nanosheets for Boosted Photocatalytic H2 Evolution

姜志民¹,

陈晴²,

郑巧清³

et al. 2020

Acta Physico Chimica Sinica

View full text Add to dashboard Cite

Sustainable photocatalytic H2 evolution has attracted extensive attention in recent years because it can address both energy shortage and environmental pollution issues. In particular, metal sulfide solid-solution photocatalysts have been widely applied in photocatalytic hydrogen generation owing to their excellent light harvesting properties, narrow enough band gap, and suitable redox potentials of conduction and valance bands. However, it is still challenging to develop low-cost and high-efficiency sulfide solid-solution photocatalysts for practical photocatalytic hydrogen evolution. Recently, 1D MnxCd1−xS nanostructures have shown superior light absorption, charge separation, and H2-evolution activity owing to their shortened diffusion pathway of carriers and high length-to-diameter ratios. Thus, 1D MnxCd1−xS nanostructures have been applied in photocatalytic H2 evolution. However, a single MnxCd1−xS photocatalyst still has some disadvantages for photocatalytic H2 evolution, such as the rapid recombination of photogenerated electron-hole pairs and low quantum efficiency. Herein, to further boost the separation of photogenerated charge carriers and H2-evolution kinetics, an in situ solvothermal method was used to synthesize the 1D/2D Schottkybased heterojunctions between the Mn0.2Cd0.8S nanorods (MCS NRs) and Ti3C2 MXene nanosheets (NSs). Furthermore, various characterization methods have been used to investigate the crucial roles and underlying mechanisms of metallic Ti3C2 MXene NSs in boosting the photocatalytic H2 evolution over the Mn0.2Cd0.8S nanorods. X-ray Diffraction (XRD), Transmission Electron Microscope (TEM), High Resolution Transmission Electron Microscopy (HRTEM), element mapping images, and X-ray Photoelectron Spectroscopy (XPS) results clearly demonstrate that hybrid low-cost Schottky-based heterojunctions have been successfully constructed for practical applications in photocatalytic H2 evolution. Additionally, the photocatalytic hydrogen evolution reaction (HER) was also carried out in a mixed solution of Na2SO3 and Na2S using as the sacrificial agents. The highest hydrogen evolution rate of the optimized 1D/2D Schottky-based heterojunction is 15.73 mmol•g −1 •h −1 , which is 6.72 times higher than that of pure MCS NRs (2.34 mmol•g −1 •h −1 ). An apparent quantum efficiency of 19.6% was achieved at 420 nm. The stability measurements of the binary photocatalysts confirmed their excellent photocatalytic stability for practical applications. More interestingly, the UV-Vis diffuse reflection spectra, photoluminescence (PL) spectrum, transient photocurrent responses, and Electrochemical Impedance Spectroscopy (EIS) Nyquist plots clearly confirmed the promoted charge separation between the MCS NRs and Ti3C2 MXene NSs. The linear sweep voltammetry also showed that the loading of MXene cocatalysts could greatly decrease the overpotential of pure MCS NRs, suggesting that the 2D Ti3C2 NSs could act as an electronic conductive bridge to improve the H2-evolution kinetics. In summary, these results show th...

show abstract

Section: The Structure and Morphologymentioning

confidence: 99%

Constructing 1D/2D Schottky-Based Heterojunctions between Mn0.2Cd0.8S Nanorods and Ti3C2 Nanosheets for Boosted Photocatalytic H2 Evolution

姜志民¹,

陈晴²,

郑巧清³

et al. 2020

Acta Physico Chimica Sinica

View full text Add to dashboard Cite

show abstract

“…For graphene, however, the Dirac cone type band structure without a band gap near the Fermi level hinders its direct applications in transistors. This has stimulated the searching for alternative materials from other 2D materials [5][6][7][8][9][10][11][12][13][14] with versatile properties, among which layered transition metal dichalcogenides (TMDs) have gained extensive attention. The band gaps of TMDs can be tuned from about 0.8 eV to 2.0 eV and are comparable with that of conventional semiconductors, enabling TMDs especially good candidates for optoelectronic applications.…”

Section: Introductionmentioning

confidence: 99%

Strain and Electric Field Controllable Schottky Barriers and Contact Types in Graphene-MoTe2 van der Waals Heterostructure

Lan

Xia²,

Huang

et al. 2020

Nanoscale Res Lett

Self Cite

View full text Add to dashboard Cite

Two-dimensional (2D) transition metal dichalcogenides with intrinsically passivated surfaces are promising candidates for ultrathin optoelectronic devices that their performance is strongly affected by the contact with the metallic electrodes. Herein, first-principle calculations are used to construct and investigate the electronic and interfacial properties of 2D MoTe2 in contact with a graphene electrode by taking full advantage of them. The obtained results reveal that the electronic properties of graphene and MoTe2 layers are well preserved in heterostructures due to the weak van der Waals interlayer interaction, and the Fermi level moves toward the conduction band minimum of MoTe2 layer thus forming an n type Schottky contact at the interface. More interestingly, the Schottky barrier height and contact types in the graphene-MoTe2 heterostructure can be effectively tuned by biaxial strain and external electric field, which can transform the heterostructure from an n type Schottky contact to a p type one or to Ohmic contact. This work provides a deeper insight look for tuning the contact types and effective strategies to design high performance MoTe2-based Schottky electronic nanodevices.

show abstract

“…In the case of type‐II mechanism, the photogenerated electrons will be transferred from CB of CN to CB of CN‐M, while holes will move from VB of CN‐M to VB of CN. The agminated holes in VB of CN cannot react with the OH − to generate the •OH radicals because of the negative VB potential of CN than OH − /•OH (1.99 eV versus NHE) . This is in conflict to the •OH radical generation detection experiment.…”

Section: Resultsmentioning

confidence: 99%

In situ construction of hierarchical graphitic carbon nitride homojunction as robust bifunctional photoelectrocatalyst for overall water splitting

Luo

Zhang

Han

et al. 2019

J of Chemical Tech & Biotech

Self Cite

View full text Add to dashboard Cite

BACKGROUND: Sustainable production of oxygen and hydrogen via catalyst-aided water splitting utilizing solar energy has attracted increasing interest. The primary issue in this field is the development of earth-abundant and active photoelectrocatalytic materials. Herein, a novel hierarchical g-C 3 N 4 /g-C 3 N 4 metal-free homojunction catalyst is synthesized through partial hydrolysis of melamine in alkali and subsequent thermal treatment.RESULTS: The hierarchical g-C 3 N 4 /g-C 3 N 4 metal-free homojunction composed of lamellas features large exposed surface area, abundant interface contact and more channels for mass transfer, making it highly effective for water splitting with a small overpotential of 500 mV at 10 mA cm −2 and low Tafel slope of 93.1 mV dec −1 for oxygen evolution reaction (OER) in 1.0 mol L −1 potassium hydroxide (KOH) solution, as well as 259 mV at 10 mA cm −2 and 109.33 mV dec −1 for hydrogen evolution reaction (HER) in 0.5 mol L −1 sulfuric acid (H 2 SO 4 ) solution. Furthermore, the overpotential and Tafel slope further decrease to 383.4 mV and 69.52 mV dec −1 for OER, 150.1 mV and 67.93 mV dec −1 for HER upon visible light irradiation, demonstrating the exceptional photo-responsive catalytic performance, which can be attributed to the direct Z-scheme homojunction resulting in effective charge transfer and •OH and superoxide free radicals produced under visible light irradiation.CONCLUSION: This work provides a facile but effective approach for the construction of metal-free OER/HER bifunctional catalyst with high photo-responsive performance, achieving higher activity for catalyst-assisted water splitting.

show abstract

Doping-induced enhancement of crystallinity in polymeric carbon nitride nanosheets to improve their visible-light photocatalytic activity

Abstract: Structural defects can greatly inhibit electron transfer in two-dimensional (2D) layered polymeric carbon nitride (CN), seriously lowering its utilization ratio of photogenerated charges during photocatalysis.

Cited by 136 publications

References 65 publications

Constructing 1D/2D Schottky-Based Heterojunctions between Mn<sub>0.2</sub>Cd<sub>0.8</sub>S Nanorods and Ti<sub>3</sub>C<sub>2</sub> Nanosheets for Boosted Photocatalytic H<sub>2</sub> Evolution

Constructing 1D/2D Schottky-Based Heterojunctions between Mn<sub>0.2</sub>Cd<sub>0.8</sub>S Nanorods and Ti<sub>3</sub>C<sub>2</sub> Nanosheets for Boosted Photocatalytic H<sub>2</sub> Evolution

Strain and Electric Field Controllable Schottky Barriers and Contact Types in Graphene-MoTe2 van der Waals Heterostructure

In situ construction of hierarchical graphitic carbon nitride homojunction as robust bifunctional photoelectrocatalyst for overall water splitting

Contact Info

Product

Resources

About