Alkali‐Assisted Synthesis of Nitrogen Deficient Graphitic Carbon Nitride with Tunable Band Structures for Efficient Visible‐Light‐Driven Hydrogen Evolution

Yu, Huijun; Shi, Run; Zhao, Yufei; Bian, Tong; Zhou, Chao; Waterhouse, Geoffrey I. N.; Wu, Li‐Zhu; Tung, Chen‐Ho; Zhang, Tierui

doi:10.1002/adma.201605148

Cited by 1,872 publications

(1,096 citation statements)

References 81 publications

Supporting

Mentioning

1,035

Contrasting

Unclassified

Order By: Relevance

“…The copolymerization with barbituric acid was studied and realized the continuous band structure modification. Zhang et al [80] proposed the nitrogen defects introduced into g-C 3 N 4 with the addition of KOH during the calcination of urea, melamine, or thiourea. The band structure of the as-obtained g-C 3 N x was also been continueus tuned.…”

Section: Band Structure Engineering Through Crystal Structure Modificmentioning

confidence: 99%

Full‐Spectrum Solar‐Light‐Activated Photocatalysts for Light–Chemical Energy Conversion

Wang

Sang

et al. 2017

Advanced Energy Materials

257

116

View full text Add to dashboard Cite

photocatalysis based on semiconductors represents another route for light energy conversion. This route endows the direct conversion of light energy into oxidation and reduction energy via charge carriers (electrons and holes) generated in the semiconductors. For instance, the photocatalytic degradation of harmful and toxic organic substances, dyes, and chemicals has been considered to be a suitable candidate for removing organic pollution from water, [5][6][7][8] where photooxidation dominates the degradation of the organic molecules. The full process of photocatalytic water splitting into H 2 and O 2 is believed to be promising for generating renewable and green energy, [9,10] and the process includes the photoreduction and photooxidation of water, respectively. The photocatalytic reduction of CO 2 can convert solar energy into chemical energy, stored as CH 4 , CO, CH 3 OH, etc. [11][12][13] These processes can help reduce the pressure of the global warming crisis and supply usable renewable energy. Due to the precise control of photocatalytic reduction and oxidation, photocatalytic molecular synthesis has also attracted much interest, which provides a sustainable pathway for green synthesis. [14][15][16] For an efficient photocatalytic process, solar light harvesting and a redox process based on photogenerated charge carriers are essential steps. Solar light harvesting consists of light absorption and charge carrier excitation steps, which can be expressed as the light utilization efficiency. The efficiency determines the total energy converted from solar light and is mostly determined by the band structure of the semiconductor applied to the photocatalytic process.The photocatalytic process has been extensively studied by examining the response of photocatalysts to UV light, due to its relatively high photonic energy. As is well known, UV light energy amounts to no more than 5% of the solar light energy. Visible light and near-infrared (NIR) light contain approximately 90% of the solar light energy. To utilize solar light in order to solve the environmental and energy crisis, visible light and NIR-light-activated photocatalysts are essential. For decades, many studies have focused on expanding the range over which a photocatalyst can utilize the solar light spectrum. In addition, there are several good reviews summarizing recent progress on UV-vis-light-activated photocatalysts, as well as strategies to improve the photocatalytic efficiency. [17][18][19][20] As is well known, the photonic energy of visible light is low, and that of NIR light is even lower. Photoinduced redox requires an initial amount of energy to activate the process; however, NIR photonic energy may be too low to realize photoinduced The realization of light-chemical energy conversion using solar light is an ideal goal in renewable energy studies. Many reports are concerned with extracting energy from solar light and the use/storage of the converted energy. Due to the progress in solar light absorption with various photocatalysts, the vari...

show abstract

Section: Band Structure Engineering Through Crystal Structure Modificmentioning

confidence: 99%

Full‐Spectrum Solar‐Light‐Activated Photocatalysts for Light–Chemical Energy Conversion

Wang

Sang

et al. 2017

Advanced Energy Materials

257

116

View full text Add to dashboard Cite

show abstract

“…8c-h). 56 The results revealed that the bandgap energy of defective g-C 3 N x decreased from 2.67 to 2.17 eV after introducing defects, which was attributed to the altered C 2p and N 2p orbitals in the conductive band of defective g-C 3 N x as compared to those of the pristine g-C 3 N 4 . All these experimental and theoretical results demonstrated that the defects in carbonbased materials play a vital role in (photo)-electrocatalysis, which highlights the need to unveil their catalytic mechanism urgently.…”

Section: Materials Chemistry Frontiers Reviewmentioning

confidence: 80%

“…urea). 56 They found that the N defect density increased with the ascending amount of KOH addition, as evidenced by the appearance of cyano groups (-CRN) and the diminishing peak of N-H bond in the FTIR spectra (Fig. 8a).…”

Section: Materials Chemistry Frontiers Reviewmentioning

confidence: 99%

“…90 Then, we present controllable strategies in preparing diverse carbon materials with defects. [48][49][50][51][52][53][54][55][56] Importantly, the defective carbon-based materials exhibit excellent ORR activities, which overcomes the common sense of the necessity for heteroatom doping. 49 Besides the carbon defect mechanism for ORR, our group further demonstrated that defects as active sites in carbon (graphene used as an ideal model material for direct instrumental identification purpose) were also functional for other electrochemical reactions, such as OER and HER, which may originate from different types of carbon defects.…”

Section: Account Of Recent Work On Defective Carbon Based Materials Fmentioning

confidence: 99%

See 1 more Smart Citation

Defect electrocatalytic mechanism: concept, topological structure and perspective

Jia

Chen

Yao

2018

Mater. Chem. Front.

133

View full text Add to dashboard Cite

Carbon-based materials have been attracting intense interest for electrocatalysis due to their various merits, such as abundance, low cost, high conductivity and tunable molecular structures. However, to date, the electrochemical activities of these electrocatalysts are mainly attributed to different active dopants (e.g. N, B, P or S), leading to a common concept that heteroatom doping is essential for carbon-based electrocatalysts. Recently, we presented a new concept where the specific topological defects could activate the oxygen reduction reaction (ORR) and developed a facile method to create such unique defects. Subsequent research has extended this new mechanism to other reactions, such as the hydrogen and oxygen evolution reactions (HER and OER) and confirmed that heteroatom doping is not essential but that these defects can serve as actives sites for electrochemical reactions. This new theory then creates a new research direction in electrocatalysis. In this short review, we summarise the origin and presentation of the defect mechanism concept, the possible topological defect structures that are effective for electrochemical reactions, the formation of desirable defects, the challenges in the synthesis and characterization of typical defects and future research directions on the electrochemical defect mechanism. Carbon-based materials have been attracting intense interest for electrocatalysis due to their various merits, such as abundance, low cost, high conductivity and tunable molecular structures. However, to date, the electrochemical activities of these electrocatalysts are mainly attributed to different active dopants (e.g. N, B, P or S), leading to a common concept that heteroatom doping is essential for carbon-based electrocatalysts. Recently, we presented a new concept where the specific topological defects could activate the oxygen reduction reaction (ORR) and developed a facile method to create such unique defects. Subsequent research has extended this new mechanism to other reactions, such as the hydrogen and oxygen evolution reactions (HER and OER) and confirmed that heteroatom doping is not essential but that these defects can serve as actives sites for electrochemical reactions. This new theory then creates a new research direction in electrocatalysis. In this short review, we summarise the origin and presentation of the defect mechanism concept, the possible topological defect structures that are effective for electrochemical reactions, the formation of desirable defects, the challenges in the synthesis and characterization of typical defects and future research directions on the electrochemical defect mechanism.

show abstract

“…Recently, certain two-dimensional (2D) materials [17][18][19], particularly bismuth-based compounds, such as BiOX (where X is Cl, Br, or I) [20]Bi 2 O 3 [21], and BiVO 4 [22], have been widely used in photocatalysis and have attracted attention for their high photocatalytic performance in the treatment of organic pollutants and nitrogen fixation in water [23,24]. In particular, 2D BiOX nanomaterials have gained more interest in recent years.…”

Section: Introductionmentioning

confidence: 99%

BiOCl/ultrathin polyaniline core/shell nanosheets with a sensitization mechanism for efficient visible-light-driven photocatalysis

et al. 2018

View full text Add to dashboard Cite

Photocatalytic technology holds great promise in renewable energy and environmental protection. Herein, we report the synthesis of a class of polyaniline-sensitized BiOCl core/shell nanosheets with visible-light photocatalytic activity by a one-step oxidative polymerization method and show how the hybrid nanosheet boosts the photocatalytic activity and stability for degradation of Rhodamine B (RhB). In this unique structure, the ultrathin polyaniline (PANI) as a shell with the thickness of about 1-2 nm, can widen the response of the catalyst to visible light to boost photocatalysis and the BiOCl core can promote the separation of photogenerated carriers from the PANI. We demonstrate that the optimized BiOCl/ PANI core/shell photocatalyst shows nearly three times higher photocatalytic activity for the degradation of RhB than pure BiOCl and also shows high stability. This work provides a new strategy for the design of a highly efficient hybrid photocatalyst driven by visible light.

show abstract

Alkali‐Assisted Synthesis of Nitrogen Deficient Graphitic Carbon Nitride with Tunable Band Structures for Efficient Visible‐Light‐Driven Hydrogen Evolution

Cited by 1,872 publications

References 81 publications

Full‐Spectrum Solar‐Light‐Activated Photocatalysts for Light–Chemical Energy Conversion

Full‐Spectrum Solar‐Light‐Activated Photocatalysts for Light–Chemical Energy Conversion

Defect electrocatalytic mechanism: concept, topological structure and perspective

BiOCl/ultrathin polyaniline core/shell nanosheets with a sensitization mechanism for efficient visible-light-driven photocatalysis

Contact Info

Product

Resources

About