SEPARATION AND PURIFICATION TECHNOLOGY
·
2018
·
IF 3.927
Yuqi Cui,Xinyi Zhang,Huixuan Zhang,Qingfeng Cheng,Xiuwen Cheng
The application of semiconductor photocatalysts in wastewater treatment has received increasingly attentions because of its potential utilization of solar energy. In this study, a novel visible-light-driven (VLD) BiOCOOH/g-C 3 N 4 composite photocatalyst was successful synthesized by a facile hydrothermal method. Afterwards, physicochemical properties of the resulting samples were investigated through X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), Brunauer-Emmett-Teller (BET) surface areas, UV–visible diffuse reflectance spectroscopy (UV–vis DRS), transient photocurrent density, Mott-Schottky (M−S) and electrochemical impedance spectroscopy (EIS) measurement. Furthermore, the visible light photocatalytic (PC) performance was evaluated through the degradation of amido black 10B dye. All results indicated that the combination of g-C 3 N 4 and BiOCOOH could exhibited greatly visible light absorbance and photo-generated charge separation efficiency, thereby resulting in the enhanced PC performance of BiOCOOH/g-C 3 N 4 composite photocatalyst. The optimal Bi/C molar rate in BiOCOOH/g-C 3 N 4 composite was determined to be 1/1, and the corresponding photodegradation rate for amido black 10B was 0.01794 min −1 , which was nearly 2.19 and 5.73 folds higher than that of pure g-C3N4 and BiOCOOH. The possible mechanism of the PC reaction was also discussed in detail. Furthermore, BiOCOOH/g-C 3 N 4 composite photocatalyst performed good reusability and stability even after four recycle utilization.
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高影响因子
MATERIALS CHEMISTRY AND PHYSICS
·
2014
·
IF 2.129
Shifu Chen,Yingfei Hu,Xiaoliang Jiang,Sugang Meng,Xianliang Fu
Developing a high-efficiency visible light photocatalyst is always a research hotspot in photocatalytic field. In this study, a novel Z-scheme photocatalyst WO 3 /g-C 3 N 4 with high efficient visible light photocatalytic activity was prepared via ball milling and heat treatment methods. The photocatalyst was characterized by X-ray powder diffraction (XRD), UV–vis diffuse reflection spectroscopy (DRS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), electron spin resonance (ESR), and photoluminescence (PL). The photocatalytic activity was evaluated by degradation of methylene blue (MB) and fuchsin (BF) under visible light illumination. The results showed that composite WO 3 /g-C 3 N 4 exhibits a much higher photocatalytic activity than a single g-C 3 N 4 . The rate constants of photocatalytic degradation of MB and BF for WO 3 (5.0 wt.%)/g-C 3 N 4 are 4.77 times and 3.84 times that of pure g-C 3 N 4 . The characterization results by physical and chemical methods demonstrated that composite WO 3 /g-C 3 N 4 is a typical Z-scheme photocatalyst. The enhancement of the photocatalytic activity may be attributed to the formation of the Z-scheme system between g-C 3 N 4 and WO 3 , which could result in the photoexcited electrons of g-C 3 N 4 and photoexcited holes of WO 3 participating in oxidation and reduction reactions, respectively.
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ChemCatChem
·
2019
·Vol. 11
·期 5
·1534-1544
·
IF 4.495
Xin Shan,Guifang Ge,Zhongkui Zhao
Graphical All-round talent ! Pyridinium alkaline ionic liquid serves as an all-rounder to fabricate graphitic carbon nitride with nitrogen defects (nitrogen vacancies and cyano groups) and extended π-conjugated system, generating a highly efficient photocatalyst for solar hydrogen production under visible light irradiation with 1284 μmol h −1 g −1 (λ>420 nm) of hydrogen evolution rate (13.6 times higher than that of bulk g-C 3 N 4 ) and 4.2 % of apparent quantum efficiency at 420 nm. Semiconductor photocatalytic hydrogen evolution from water splitting using solar energy is one of the most potential strategies for settling the energy crisis, but a bottleneck is occurred in developing a highly efficient photocatalyst. Herein, we successfully fabricated a tubular g-C 3 N 4 with nitrogen defects (including both nitrogen vacancies and cyano groups) and extended π-conjugated system, wherein the nitrogen defects and extended π-conjugated system were conveniently introduced during thermal polymerization of the pyridinium alkaline ionic liquid-modified hydrogen-bonding melamine-cyanuric acid supramolecular (PHMCS) pre-aggregates towards carbon nitride with hexagonal cylinder morphology formed by the pyridinium alkaline ionic liquid-assisted hydrothermal process of low-cost melamine, in which the added trace pyridinium alkaline ionic liquid serves as an all-rounder with three roles including the promoting agent towards the transformation of melamine to cyanuric acid for constructing PHMCS, nitrogen defects making agent, and the electronic-tuning agent regarding of the as-formed carbon nitride. The tubular structure enhances the light scattering and improves the accessibility of active sites. Meanwhile, the high charge transfer efficiency, broad optical absorption region, and suitable energy band positions are related to both the introduction of nitrogen defects by alkali of ionic liquid and the extended π-electron delocalization in the conjunction carbon nitride networks. As a consequence, the resulted carbon nitride using optimized amount of pyridinium alkaline ionic liquid (AIL-2.0-CN) photocatalyst exhibited a high hydrogen evolution rate of 1284 μmol h −1 g −1 (λ>420 nm) with an apparent quantum efficiency of 4.2 % at 420 nm, which is 13.6 times higher than that of bulk g-C 3 N 4 (B−CN), and even 3.5 folds much higher than the one (SHPY−CN) prepared by the similar process to that for AIL-2.0-CN except for the replacement of pyridinium alkaline ionic liquid by a mixture containing a corresponding amount of pyridine and sodium hydroxide, suggesting the promoting effect resulting from the unique characteristic of pyridinium alkaline ionic liquid. Based on the unique physicochemical properties and the molecules- adjustability, the developed alkaline ionic liquid assisted strategy can open an avenue for designing and preparing excellent g-C 3 N 4 based photocatalysts with tunable geometric and electronic structures for solar hydrogen production.
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高影响因子
ACS Applied Materials & Interfaces
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2024
·
IF 8.3
Jia Yang,Rong Wang,Xiaorui Sun,Yan Li,Jian Liu,Xiaojun Kuang
The use of novel two-dimensional MXene materials and conventional g-C3N4 photocatalysts to fabricate the composites for hydrogen evolution reaction (HER) has attracted much attention, for which there is plenty of room for the enhancement of hydrogen evolution rates particularly under visible light and photostability. Herein, g-C3N4 was modified by copolymerization of malonamide and melamine and used to fabricate the ternary composites of Au particles and Ti3C2 MXene, and based on the synergistic effect, the composites enhanced the hydrogen evolution rates by 2.1, 99.8, and ∞ times compared with the unmodified g-C3N4 under UV, simulated sunlight, and visible light illumination, respectively. Moreover, the composite exhibited a sustained hydrogen evolution capacity in the cycle test for up to 120 h. Theoretical calculations and experimental results indicated that the hot electrons of Au are injected into the modified g-C3N4 and transferred to Ti3C2 simultaneously along with the photogenerated electrons of the modified g-C3N4 and then further transferred to Au, forming a photogenerated electron transfer channel of Au and modified g-C3N4 → Ti3C2 → Au within the composite. Ti3C2 acts as a bridge for fast separation of photogenerated electrons and holes on Au and modified g-C3N4, playing a key role in the enhanced photocatalytic performance. In addition, the visible light absorption ability of Au also positively contributed to the enhancement of visible light photocatalytic performance by providing hot electrons. Therefore, the selection of suitable cocatalysts for the design of composites is a crucial research direction to improve the photocatalytic performance and photostability of photocatalysts.
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高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2020
·Vol. 55
·期 24
·10712-10724
·
IF 3.553
Li Wenhua,Chen Qianqiao,Zhong Qin
The nickel sulfide (NiS) nanoparticles were anchored on the mesoporous graphitic carbon nitride (g-C 3 N 4 ) by one-pot calcination with sulfur powder as sulfur source and pore-forming agent. It is the first attempt to use the g-C 3 N 4 /NiS as a counter electrode (CE) for quantum-dot-sensitized solar cells. The g-C 3 N 4 /NiS co-catalyst based on 0.74 wt% NiS loading for S 2− n reduction obtained a low interface charge transfer resistance ( R ct ) of 1.08 Ω. The power conversion efficiency of the QDSSC assembled with ZnSe/CdS/CdSe/ZnSe-sensitized TiO 2 photoanode and g-C 3 N 4 /NiS CE is up to 5.64%, which is 3.05 times as high as that of pure g-C 3 N 4 CE. The enhancement of cell efficiency is attributed to the synergistic effects of excellent morphology of g-C 3 N 4 and its co-catalysis with NiS nanoparticles. The mesoporous architecture contributes a large specific surface area and fast electrolyte transfer channels, and the coupling of g-C 3 N 4 with NiS promotes the transfer of charge between the interface g-C 3 N 4 /NiS and electrolytes. The presented strategy for fabricating mesoporous architecture with g-C 3 N 4 /NiS uses low-cost raw materials and a simple preparation method, which provides a feasible route to enhance the electrocatalytic activity of g-C 3 N 4 .
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高影响因子
RSC Advances
·
2020
·Vol. 10
·期 47
·28059-28065
·
IF 3.119
Yunqi Fu,Mang Zheng,Qi Li,Liping Zhang,Shuai Wang,V. V. Kondratiev,Baojiang Jiang
Benzylamine coupling is a very important reaction for the synthesis of imine but still faces many challenges. Herein, we present a highly effective strategy towards the coupling reaction by using environmentally friendly catalysts. These catalysts are composed of Cu/Cu2O/Cu3N heterostructures supported by C3N4 tubes and the composites were synthesized by one-step hydrothermal treatment followed by calcination. Cu2O, Cu3N, and C3N4 all are responsive to visible light and the heterojunction formed can greatly enhance the charge separation. When used as photocatalysts for oxidative self-coupling of benzylamine at a low temperature of 323 K in air, Cu/Cu2O/Cu3N/C3N4 was able to give conversion and selectivity values of up to 99% and 98%, respectively. The high efficiency of the catalysts is attributable to their ability to generate large quantities of free radicals (such as ·OH and ·O2−) under visible-light irradiation.
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高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
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2022
·
IF 7.139
Xuecheng Liu,Linjie Yan,Xiting Hu,Hongli Feng,Bingke Guo,Xia Ha,Hui Xu,Ruiqi Wang,Xuemei Tan,Hongyu Huang
A series of MnO 2 /g-C 3 N 4 composites with different exposed crystal plane were successfully prepared by different synthesized method. UV–Vis, PL , ESR and electrochemical results suggest that the visible-light absorbance, photoexcited electron-separation efficiency and oxygen defects are greatly dependent on the exposed crystal-faceted MnO 2 supported on g-C 3 N 4 . The experimental results display that the exposed crystal plane of MnO 2 have great influences on the photocatalytic hydrogen evolution performance, and the m-MnOCN composite with exposed (111) crystal plane exhibits superior photocatalytic performance for the release of H 2 under visible light irradiation , followed by the order of b-MnOCN [002]> p-MnOCN [110]. Moreover, Mechanism studies have shown that the possible mechanism of photocatalytic hydrogen evolution reaction is Z-scheme mechanism.
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高影响因子
NEW JOURNAL OF CHEMISTRY
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2021
·Vol. 45
·期 36
·16750-16759
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IF 3.591
Yining Zheng,Cundi Wei,Qi An,Jinsheng Yu,Shaonan Xu,Lina Li
The aluminum alloy is used as the aluminum source, together with melamine and cyanuric acid, in a water reaction system to obtain the precursor of Al2O3/g-C3N4 through self-assembly in one step, and then calcined to obtain the Al2O3/g-C3N4 composite photocatalytic material. γ-Al2O3 has a defect site that can accept g-C3N4 electrons and can bind well with g-C3N4. The addition of γ-Al2O3 changed the morphology of g-C3N4 into a damaged tubular structure with many irregular pores. Also, the specific surface area increased to about 1.2 times that of g-C3N4, and the light absorption edge was extended to 500 nm. In addition, the position of the valence band of g-C3N4 was also changed. Compared with g-C3N4, Al2O3/g-C3N4 has better photocatalytic performance, and the degradation rate of dye rhodamine B (RhB) is about 1.70 times that of g-C3N4.
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高影响因子
RSC Advances
·
2021
·Vol. 11
·期 53
·33373-33379
·
IF 3.361
Lejie Zhu,Jianmin Luo,Guohui Dong,Yun Lu,Yinlong Lai,Jun Liu,Guanmei Chen,Yi Zhang
As a kind of metal-free organic semiconductor photocatalyst, g-C3N4 has been widely explored for use in photocatalysis. However, the low quantum yield, small absorption range, and poor conductivity limit its large-scale application. Introducing another kind of semiconductor, particularly an oxide semiconductor, can result in some unexpected properties, such as an improved change transfer, enhanced light absorption, and better conductivity. In this work, CuO/g-C3N4 is successfully prepared through an impregnation and post-calcination method. A series of measurements support the formation of an organic-inorganic hybrid p–n heterojunction at the CuO (p-type) and g-C3N4 (n-type) interface. Furthermore, the photoactivity of the composite is evaluated via photocatalytic NO removal and the visible degradation of rhodamine B (RhB). Results show that the photocatalytic properties of CuO/g-C3N4 are almost twice as high as those of g-C3N4. In comparative tests, the photocatalytic degradation performance of Mix-CuO/g-C3N4 (the mixture of CuO and g-C3N4 nanosheets prepared by mechanically mixing) is even lower than that of pure g-C3N4. The degradation of RhB is only 19.7% under visible light after 30 min of irradiation. The improvement in the photoactivity of CuO/g-C3N4 results from the built-in electric field close to the formed p–n heterojunction, which switches the electron transfer mechanism from a double-charge transfer mechanism to a Z-scheme mechanism. In addition, the formed p–n heterojunction favors charge transfer, and thus the photocatalytic performance is significantly improved.
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高影响因子
Materials Research Express
·
2021
·Vol. 8
·期 5
·055504
·
IF 1.62
Fengpo Yan,Hao Zhang,Yu Zhang,Fugui Yang
0.3 mol% platinum loaded g-C3N4 sample was prepared by photoreduction method to study the long-term stability of photocatalysts. For the first time, we have discovered the oriented attachment (OA) mechanism growth of Pt nanoparticles on g-C3N4 solid surface, which is completely different from Ostwald ripening (OR) or particle migration and coalescence (PMC) that previously reported. The Pt nanoparticles perform Brownian motion on the surface of g-C3N4 support under the collision of liquid molecules, then two or more nanoparticles attach together via the crystallographic orientation to construct larger ones. Al2O3 film prepared by atomic layer depositon was introduced to inhibit the Brownian motion of Pt nanoparticles. It is found that as the increase of the Al2O3 growth cycles, the photocatalytic hydrogen production of Pt/g-C3N4 coated by Al2O3 increase from 1.14 mmolg−1h−1 to 2.08 mmolg−1h−1 and then decrease to 1.4 mmolg−1h−1, and the apparent quantum efficiency (QE) also increase from 1.2% to 2.1% and then decrease to 1.4%. Meanwhile, the long-term stability of photocatalyst always increases. This work has revealed new pathway of photocatalytic nanoparticle growth on solid surface and proposed the method to prevent it.
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高影响因子
JOURNAL OF ENVIRONMENTAL ENGINEERING
·
2024
·Vol. 150
·期 11
·04024050
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IF 1.6
Huanglong Zhuang,Guiyang Yan,Jiwei Wang,Zhuang Hu,Siqi Yan,Yinkai Sun,Tuanyu Guo,Jianshe Hu,Aikebaier Reheman
This study presents a groundbreaking composite adsorbent, STB@MOF-808-SH, developed through the innovative amalgamation of thiol-functionalized metal-organic framework material (MOF-808-SH) with sulfur-doped C3N4 tubular bundles (STB), targeting the effective elimination of toxic mercury [Hg(II)] ions from polluted water. Our investigation explores crucial determinants of the adsorption process, including pH, initial Hg(II) concentration, and the impact of coexisting ions, while revealing the significant enhancement in mercury ion removal efficiency and adsorption capacity due to the synergistic interaction between STB and MOF-808-SH. Remarkably, under optimal conditions at pH 4.0, STB@MOF-808-SH achieves a removal rate of 91.35% and an impressive adsorption capacity of 228.38 mg/g. These outcomes suggest that the development of the STB@MOF-808-SH composite adsorbent introduces a novel and efficacious approach to tackling water pollution issues, highlighting its potential as a cost-effective and efficient solution for the remediation of toxic Hg(II) ions in wastewater.
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高影响因子
EUROPEAN JOURNAL OF INORGANIC CHEMISTRY
·
2016
·Vol. 2016
·期 34
·5387-5392
·
IF 2.686
Liang Zhou,Lingzhi Wang,Jinlong Zhang,Juying Lei,Yongdi Liu
Graphical A heterogeneous photo-Fenton system (Fe 2 O 3 /g-C 3 N 4 /H 2 O 2 /visible light) has been developed for highly efficient and stable catalytic degradation of organic pollutants in water. The combination of the Fenton's reagent Fe 2 O 3 /H 2 O 2 and the photocatalyst g-C 3 N 4 greatly enhances the rate of the Fenton's reaction with the assistance of the photocatalytic process. In this study, a highly efficient heterogeneous photo-Fenton system (Fe 2 O 3 /g-C 3 N 4 /H 2 O 2 /visible light) has been developed. The heterogeneous catalyst Fe 2 O 3 /g-C 3 N 4 in this system was successfully prepared by growing Fe 2 O 3 nanoparticles on the surface of g-C 3 N 4 . The Fe 2 O 3 nanoparticles could achieve high dispersion on the surface of g-C 3 N 4 and form a heterojunction with g-C 3 N 4 to improve the charge separation. In addition, the combination of the Fenton's reagent Fe 2 O 3 /H 2 O 2 and the photocatalyst g-C 3 N 4 greatly enhances the rate of the Fenton's reaction with the assistance of the photocatalytic process. The results showed that the Fe 2 O 3 /g-C 3 N 4 catalyst had a superior catalytic activity as compared with the single component of Fe 2 O 3 or g-C 3 N 4 and the mechanical mixture of Fe 2 O 3 and g-C 3 N 4 . The catalyst prepared with 3 mL of FeCl 3 aqueous solution shows the best photo-Fenton photocatalytic efficiency with a reaction rate constant of 0.02461 mg L –1 min –1 , which is about 45.4, 8.4 and 7.2 times larger than that of pure Fe 2 O 3 (0.0005418 mg L –1 min –1 ), pure g-C 3 N 4 (0.00294 mg L –1 min –1 ) and the mechanically mixed Fe 2 O 3 /g-C 3 N 4 (0.0034 mg L –1 min –1 ), respectively. A possible mechanism for the visible-light-irradiated photo-Fenton photocatalysis is proposed, and the Fe 2 O 3 /g-C 3 N 4 catalyst exhibited stable performance without obvious loss of catalytic activity after four successive runs, showing a good application prospect for the photo-oxidative degradation of organic contaminants in wastewater.
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高影响因子
危险品化学品经营许可证（带存储）