2D/2D/0D TiO2/C3N4/Ti3C2 MXene composite S-scheme photocatalyst with enhanced CO2 reduction activity

He, Fang; Zhu, Bicheng; Cheng, Bei; Wang, Yuanyuan; Ho, Wingkei; Macyk, Wojciech

doi:10.1016/j.apcatb.2020.119006

Cited by 739 publications

(372 citation statements)

References 64 publications

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“…Beside immobilization of BiOI, coupling BiOI with a nonmetal co-catalyst to construct an S-scheme heterojunction is also an effective way to improve its performance 11, [29][30][31][32][33][34][35][36][37] . Usually, semiconductors with narrow band gap are employed as the cocatalyst in building S-scheme heterojunctions, such as CdS, MoS2, C3N4, and Bi2O3 [38][39][40][41] . In fact, graphene quantum dots (GQDs) can also act as the co-catalyst in constructing S-scheme heterojunctions.…”

Section: Introductionmentioning

confidence: 99%

Fabrication of Graphene Quantum Dots Modified BiOI/PAN Flexible Fiber with Enhanced Photocatalytic Activity

He¹,

Chen²,

Luo³

et al. 2020

Acta Physico Chimica Sinica

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In environment remediation, photocatalytic oxidation is a promising technique for removing organic pollutants. Compared to adsorption, biodegradation, and chemical oxidation, photocatalytic oxidation can eliminate organic pollutants completely, conveniently, and cheaply in an environmentally friendly manner. Visible-light-driven photocatalytic oxidation is particularly advisable because of the high proportion of visible light energy in solar energy. Bismuth oxyiodide (BiOI) is a promising visible-light-driven photocatalyst for the oxidization of pollutants, not only because of its narrow band gap, but also for its relatively low valence band (VB), which is adequate for photogenerated holes to oxidize a variety of organic compounds. However, the shortcomings of BiOI powder, such the difficulty of recycling it, its low surface area, and fast carrier recombination, limit its practical applications. Meanwhile, the flexibility and hierarchical structure of photocatalysts are particularly advisable because these properties are beneficial for the convenient operation, recycling, and performance improvement of these materials. Herein, based on an electro-spun polyacrylonitrile (PAN) nanofiber substrate, a hierarchical BiOI/PAN fiber was prepared through an in situ reaction. In the as-prepared BiOI/PAN fibers, BiOI flakes were aligned vertically and uniformly around the PAN fibers. BiOI nuclei generated from preintroduced Bi(III) in the PAN fiber act as seeds for the growth of BiOI nanoplates, which is crucial for the formation of a hierarchical structure. Such a hierarchical structure can improve both the light absorption and carrier generation of the BiOI/PAN fibers, as demonstrated by UV-Vis diffuse reflectance spectra and photoluminescence emission. Therefore, the BiOI/PAN fibers exhibited higher photocatalytic activity than BiOI powder. When the BiOI/PAN fibers were decorated with pre-prepared graphene quantum dots (GQDs), a GQD-modified BiOI/PAN fibrous composite (GQD-BiOI/PAN) was fabricated. The morphology of the obtained GQD-BiOI/PAN fibers was nearly the same as that of the BiOI/PAN fibers. A step-scheme (S-scheme) heterojunction was formed between the GQDs and BiOI, which was confirmed by the fabrication method, photoluminescence emission, reactive radical tests, and XPS analysis. This kind of S-scheme heterojunction can not only effectively suppress the recombination of photogenerated holes, but can also reserve the more reductive electrons on the lowest unoccupied molecular orbital of GQDs and the more oxidative holes on the VB of BiOI, for the photocatalytic degradation of phenol. Because of the fibrous hierarchical structure and S-scheme heterojunction, GQD-BiOI/PAN outperformed BiOI nanoparticles and BiOI/PAN nanofibers in the photocatalytic oxidation of phenol under visible light. In addition, because of tight bonding, GQD-BiOI/PAN can be tailored and operated by hand, which is convenient for recycling. During recycling, no obvious loss of sample or decrease in photocatalytic activity was observed. This w...

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Section: Introductionmentioning

confidence: 99%

Fabrication of Graphene Quantum Dots Modified BiOI/PAN Flexible Fiber with Enhanced Photocatalytic Activity

He¹,

Chen²,

Luo³

et al. 2020

Acta Physico Chimica Sinica

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“…Among the semiconductors with high valence band (VB) potential, TiO 2 , as an ultraviolet‐responsive semiconductor with a bandgap of 3.2 eV, is the most studied photocatalytic semiconductor. [ 24–28 ] As its energy band structure is capable of forming S‐scheme with g‐C 3 N 4 , a wide range of g‐C 3 N 4 /TiO 2 composites have been synthesized for CO 2 reduction, [ 27 ] organics degradation, [ 29–33 ] H 2 production, [ 34,35 ] and N 2 O decomposition. [ 36 ] Although the g‐C 3 N 4 /TiO 2 composites have various morphologies, the contact modes of g‐C 3 N 4 and TiO 2 can be simply classified as point‐to‐face contact [ 32 ] and face‐to‐face contact.…”

Section: Introductionmentioning

confidence: 99%

“…[ 36 ] Although the g‐C 3 N 4 /TiO 2 composites have various morphologies, the contact modes of g‐C 3 N 4 and TiO 2 can be simply classified as point‐to‐face contact [ 32 ] and face‐to‐face contact. [ 27,29,37 ] As the specific 1D electron transfer and narrow point‐to‐face transfer channel greatly reduce the electron transfer efficiency, an efficient face‐to‐face contact was adopted in more g‐C 3 N 4 /TiO 2 composites. As the intensity of light decays exponentially in a semiconductor, g‐C 3 N 4 /TiO 2 composites with hollowsphere structure, [ 37 ] porous structure, [ 38 ] and flower structure [ 39 ] were widely prepared to increase their specific surface area.…”

Section: Introductionmentioning

confidence: 99%

Construction of an Ultrathin S‐Scheme Heterojunction Based on Few‐Layer g‐C₃N₄ and Monolayer Ti₃C₂T_x MXene for Photocatalytic CO₂ Reduction

et al. 2020

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As charge carriers transfer is critical for the photocatalytic activity enhancement of step‐scheme (S‐scheme) photocatalysts, facile construction of a S‐scheme heterojunction with great contact area and strong interaction between the compositions is highly desirable. Herein, an ultrathin S‐scheme heterojunction g‐C3N4/TiO2/C (SL‐EAC) consisting of few‐layer g‐C3N4 nanosheets on monolayer Ti3C2Tx MXene converted TiO2/C is prepared through an electrostatic self‐assembly and calcination method. The monolayer Ti3C2Tx can not only prevent g‐C3N4 from agglomerating through forming close contact with g‐C3N4, but its conversion to TiO2/C during calcination can build a bridge between the relatively inert TiO2 and multigroup‐terminated Ti3C2Tx, which indirectly enhances the interface contact between TiO2/C and g‐C3N4. SL‐EAC with a thickness of around 5 nm shows much better photocatalytic CO2 reduction performance than g‐C3N4, TiO2/C prepared by calcination of monolayer Ti3C2Tx and g‐C3N4/TiO2/C (EAC) prepared by the same method but monolayer Ti3C2Tx is altered by multilayer Ti3C2Tx. The excellent performance of SL‐EAC is attributed to the large contact area between g‐C3N4 and TiO2/C, which is conducive to the S‐scheme transfer of photogenerated charge carriers. Moreover, the samples prepared using different methods are also investigated, which further confirms the great contact area and strong interaction between the composites in ultrathin SL‐EAC.

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“…3b displays the high-resolution C 1s spectrum, in which two peaks are located at 284.8 and 288.3 eV, respectively. The peak at 288.3 eV is attributed to the sp 2 -hybridized carbon 14, 30,31 . While the peak at 284.8 eV is assigned to adventitious carbon on the surface 32 .…”

Section: Xps and Elemental Analysesmentioning

confidence: 99%

2D/2D FeNi-LDH/g-C3N4 Hybrid Photocatalyst for Enhanced CO2 Photoreduction

李瀚¹,

李芳²,

余家国³

et al. 2020

Acta Physico Chimica Sinica

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2D/2D/0D TiO2/C3N4/Ti3C2 MXene composite S-scheme photocatalyst with enhanced CO2 reduction activity

Cited by 739 publications

References 64 publications

Fabrication of Graphene Quantum Dots Modified BiOI/PAN Flexible Fiber with Enhanced Photocatalytic Activity

Fabrication of Graphene Quantum Dots Modified BiOI/PAN Flexible Fiber with Enhanced Photocatalytic Activity

Construction of an Ultrathin S‐Scheme Heterojunction Based on Few‐Layer g‐C₃N₄ and Monolayer Ti₃C₂T_x MXene for Photocatalytic CO₂ Reduction

2D/2D FeNi-LDH/g-C<sub>3</sub>N<sub>4</sub> Hybrid Photocatalyst for Enhanced CO<sub>2</sub> Photoreduction

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2D/2D/0D TiO2/C3N4/Ti3C2 MXene composite S-scheme photocatalyst with enhanced CO2 reduction activity

Cited by 739 publications

References 64 publications

Fabrication of Graphene Quantum Dots Modified BiOI/PAN Flexible Fiber with Enhanced Photocatalytic Activity

Fabrication of Graphene Quantum Dots Modified BiOI/PAN Flexible Fiber with Enhanced Photocatalytic Activity

Construction of an Ultrathin S‐Scheme Heterojunction Based on Few‐Layer g‐C3N4 and Monolayer Ti3C2Tx MXene for Photocatalytic CO2 Reduction

2D/2D FeNi-LDH/g-C<sub>3</sub>N<sub>4</sub> Hybrid Photocatalyst for Enhanced CO<sub>2</sub> Photoreduction

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Construction of an Ultrathin S‐Scheme Heterojunction Based on Few‐Layer g‐C₃N₄ and Monolayer Ti₃C₂T_x MXene for Photocatalytic CO₂ Reduction