Hollow TiO2 Microsphere/Graphene Composite Photocatalyst for CO2 Photoreduction

In an attempt to improve the photocatalytic activity of anatase TiO2, we developed a composite photocatalyst composed of hollow TiO2 microspheres (hTS) and graphene. The hTS were prepared through a two-step hydrothermal process, where SiO2 microspheres with desirable diameters of 100–400 nm were used as sacrificial templates. Accordingly, the effect of the hTS cavity size on the activity of the catalyst in wet CO2 photoreduction (CO2PR) was studied. Furthermore, it was established that the hydrothermal pH value crucially influences the photocatalytic activity of the hTS photocatalyst, as well as its composition and microstructure. The hTS photocatalyst was also combined with graphene (0–90 wt%) to improve its photocatalytic activity. This study provides insight into the optimal microsphere diameter, hydrothermal pH value, and graphene/hTSx ratio required for designing hollow microsphere-based photocatalysts with enhanced CO2PR performances.

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Insight into reaction pathways of CO2 photoreduction into CH4 over hollow microsphere Bi2MoO6-supported Au catalysts

Chemical Engineering Journal ◽

10.1016/j.cej.2021.133540 ◽

2021 ◽

pp. 133540

Author(s):

Wenjie He ◽

Yuechang Wei ◽

Jing Xiong ◽

Zhiling Tang ◽

Weiyu Song ◽

...

Keyword(s):

Hollow Microsphere ◽

Reaction Pathways ◽

Co2 Photoreduction ◽

Insight Into

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Opposite photocatalytic activity orders of low-index facets of anatase TiO2 for liquid phase dye degradation and gaseous phase CO2 photoreduction

Physical Chemistry Chemical Physics ◽

10.1039/c4cp01488j ◽

2014 ◽

Vol 16 (29) ◽

pp. 15675 ◽

Cited By ~ 37

Author(s):

Liqun Ye ◽

Jin Mao ◽

Tianyou Peng ◽

Ling Zan ◽

Youxiang Zhang

Keyword(s):

Photocatalytic Activity ◽

Liquid Phase ◽

Gaseous Phase ◽

Dye Degradation ◽

Anatase Tio2 ◽

Co2 Photoreduction

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Formation of TiO2/Ti Composite Photocatalyst Film by 2-Step Mechanical Coating Technique

Materials Science Forum ◽

10.4028/www.scientific.net/msf.675-677.1229 ◽

2011 ◽

Vol 675-677 ◽

pp. 1229-1232 ◽

Cited By ~ 10

Author(s):

Yun Lu ◽

Hiroyuki Yoshida ◽

Hiroyuki Nakayama ◽

Liang Hao ◽

Mitsuji Hirohashi

Keyword(s):

Photocatalytic Activity ◽

Composite Film ◽

Random Distribution ◽

High Photocatalytic Activity ◽

Anatase Tio2 ◽

Composite Photocatalyst ◽

Simple Process ◽

Coating Technique ◽

Nonuniform Thickness ◽

Mechanical Coating

In the present work, 2-step mechanical coating technique (2-step MCT), an advanced MCT, was proposed and carried out to form TiO2/Ti composite photocatalyst film with anatase TiO2. The microstructures and photocatalytic activity of the composite film were investigated. The results show that the proposed 2-step MCT is a simple process for forming TiO2/Ti composite film. The composite film has a microstructure with a nonuniform thickness, like random distribution islands. The TiO2/Ti composite film has high photocatalytic activity, which is related with crystallinity and volume of the TiO2 in the composite film.

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Synthesis of tapered tetragonal nanorods of anatase TiO2 with enhanced photocatalytic activity via a sol–hydrothermal process mediated by H2O2 and NH3

Journal of Materials Chemistry A ◽

10.1039/c5ta02396c ◽

2015 ◽

Vol 3 (29) ◽

pp. 15265-15273 ◽

Cited By ~ 10

Author(s):

Linlin Zhang ◽

Long Tian ◽

Yongxin Liu ◽

Taixing Tan ◽

Dan Liu ◽

...

Keyword(s):

Photocatalytic Activity ◽

Band Structure ◽

Surface Area ◽

Electronic Band Structure ◽

Hydrothermal Process ◽

Anatase Tio2 ◽

Large Surface Area ◽

Electronic Band ◽

Photocatalytic Activities ◽

Unique Surface

Enhanced photocatalytic activities of tapered tetragonal nanorods of anatase TiO2 mediated by H2O2 and NH3 were ascribed to their large surface area, unique surface heterojunction and superior electronic band structure.

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Solvothermal-Assisted Synthesis of Biomass Carbon Quantum Dots/Bismuth Oxyiodide Microflower for Enhanced Photocatalytic Activity

NANO ◽

10.1142/s1793292018500315 ◽

2018 ◽

Vol 13 (03) ◽

pp. 1850031 ◽

Cited By ~ 4

Author(s):

Xin Yao ◽

Changchang Ma ◽

Hai Huang ◽

Zhi Zhu ◽

Hongjun Dong ◽

...

Keyword(s):

Quantum Dots ◽

Photocatalytic Activity ◽

Separation Efficiency ◽

Carbon Quantum Dots ◽

Biomass Carbon ◽

Electron Transfer Mechanism ◽

Composite Photocatalyst ◽

Major Activity ◽

Facile Solvothermal Method ◽

Insight Into

In this paper, the biomass carbon quantum dots (CQDs) modified flower-like BiOI (CQDs/BiOI) composite photocatalyst was synthesized by a facile solvothermal method. Compared with the pristine BiOI, the biomass CQDs/BiOI exhibited outstanding photocatalytic activity for degradation of the typical methylene blue (MB) under visible light irradiation since the biomass CQDs could act as electron acceptors to effectively facilitate the separation efficiency of photon-generated carriers and prolong their lifetime. Furthermore, the mechanism detection experiment showed that the [Formula: see text] and H[Formula: see text] were major activity species, and the photocatalytic electron transfer mechanism was further investigated. This work provided a new insight into biomass CQDs effects and took an important step toward the development of improving Bi-based semiconductor photocatalyst activity.

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Photodegradation of Microcystin-LR Using Visible Light-Activated C/N-co-Modified Mesoporous TiO2 Photocatalyst

Materials ◽

10.3390/ma12071027 ◽

2019 ◽

Vol 12 (7) ◽

pp. 1027 ◽

Cited By ~ 12

Author(s):

Tamer Khedr ◽

Said El-Sheikh ◽

Adel Ismail ◽

Ewa Kowalska ◽

Detlef Bahnemann

Keyword(s):

Photocatalytic Activity ◽

Visible Light ◽

Specific Surface ◽

Surface Area ◽

Specific Surface Area ◽

Photoelectron Spectroscopy ◽

Ph Value ◽

Hydrothermal Process ◽

Tio2 Photocatalyst ◽

X Ray

Microcystin-LR (MC-LR), a potent hepatotoxin produced by the cyanobacteria, is of increasing concern worldwide because of severe and persistent impacts on humans and animals by inhalation and consumption of contaminated waters and food. In this work, MC-LR was removed completely from aqueous solution using visible-light-active C/N-co-modified mesoporous anatase/brookite TiO2 photocatalyst. The co-modified TiO2 nanoparticles were synthesized by a one-pot hydrothermal process, and then calcined at different temperatures (300, 400, and 500 °C). All the obtained TiO2 powders were analyzed by X-ray diffraction (XRD), Raman spectroscopy, transmission electron microscope (TEM), specific surface area (SSA) measurements, ultraviolet-visible diffuse reflectance spectra (UV-vis DRS), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FTIR) spectroscopy, and photoluminescence (PL) analysis. It was found that all samples contained mixed-phase TiO2 (anatase and brookite), and the content of brookite decreased with an increase in calcination temperature, as well as the specific surface area and the content of non-metal elements. The effects of initial pH value, the TiO2 content, and MC-LR concentration on the photocatalytic activity were also studied. It was found that the photocatalytic activity of the obtained TiO2 photocatalysts declined with increasing temperature. The complete degradation (100%) of MC-LR (10 mg L−1) was observed within 3 h, using as-synthesized co-modified TiO2 (0.4 g L−1) at pH 4 under visible light. Based on the obtained results, the mechanism of MC-LR degradation has been proposed.

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Significant Enhancement of the Visible Light Photocatalytic Properties in 3D BiFeO3/Graphene Composites

Nanomaterials ◽

10.3390/nano9010065 ◽

2019 ◽

Vol 9 (1) ◽

pp. 65 ◽

Cited By ~ 8

Author(s):

Jiquan Li ◽

Youyan Wang ◽

Huan Ling ◽

Ye Qiu ◽

Jia Lou ◽

...

Keyword(s):

Photocatalytic Activity ◽

Visible Light ◽

Degradation Rate ◽

Photocatalytic Performance ◽

Bismuth Ferrite ◽

Hydrothermal Process ◽

Photocatalytic Properties ◽

Graphene Composite ◽

3D Architecture ◽

Visible Light Photocatalytic

Bismuth ferrite (BiFeO3, BFO) submicron cubes and 3D BFO/graphene composite materials were synthesized by a simple hydrothermal process. The crystallization processes of the 3D BFO/graphene composites with different graphene oxide (GO) concentrations were studied for their visible light photocatalytic properties. Compared to the single BFO submicron cubes, 3D BFO/graphene composites have greatly improved photocatalytic activity. A high photocatalytic performance is obtained at a GO concentration of 3 mg/mL, with the degradation rate of methylene blue (MB) dye reaching up to 92% in 140 min. The enhancement of photocatalytic activity can be attributed to the large specific surface area and 3D architecture of 3D composites, which provide more transport paths to effectively improve the separation rate of photo-generated electrons and holes. Therefore, 3D BFO/graphene composites have a broad prospect of application in the field of photocatalysis.

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Enhanced Photocatalytic Activity of Hybrid rGO@TiO2/CN Nanocomposite for Organic Pollutant Degradation under Solar Light Irradiation

Catalysts ◽

10.3390/catal11091023 ◽

2021 ◽

Vol 11 (9) ◽

pp. 1023

Author(s):

Martina Kocijan ◽

Lidija Ćurković ◽

Tina Radošević ◽

Matejka Podlogar

Keyword(s):

Electron Microscopy ◽

Aqueous Solution ◽

Photocatalytic Activity ◽

Tio2 Nanoparticles ◽

Photoelectron Spectroscopy ◽

Diffuse Reflectance Spectroscopy ◽

Ph Value ◽

Organic Pollutant ◽

Anatase Tio2 ◽

X Ray

The three-component hybrid (rGO/TiO2/CN) nanocomposite was prepared in order to enhance the photocatalytic properties of anatase TiO2 nanoparticles (NPs) under solar-like irradiation. The rGO/TiO2/CN was prepared in a mixture of the reduced graphene oxide (rGO, 8 wt%), anatase TiO2 nanoparticles (NPs), and graphitic carbon nitride (g-C3N4, 16 wt%). It was self-assembled through the one-step hydrothermal method, followed by an annealing process. The photocatalyst was thoroughly characterized by means of X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), the Brunauer-Emmett-Teller (BET) nitrogen adsorption/desorption technique and UV-Vis diffuse reflectance spectroscopy (DRS). The photocatalytic activity of the TiO2, TiO2/rGO, TiO2/CN and hybrid rGO/TiO2/CN nanocomposite was studied through the degradation of a rhodamine B (RhB) aqueous solution under solar-like irradiation. The results showed that the highest photocatalytic activity was achieved by the rGO/TiO2/CN mixture, which can be attributed to the synergistic effect of the incorporation of both rGO and g-C3N4 with TiO2. Further, the influence of the pH value of the RhB dye aqueous solution and different water matrix (Milli-Q, tap, and alkaline water) on the photocatalytic efficiency of the rGO/TiO2/CN nanocomposite was examined. In addition, a recycle test was performed for hybrid rGO@TiO2/CN to investigate the effectiveness of the photodegradation of RhB dye in three successive cycles. The conducted results indicate that the pH value of RhB dye aqueous solution and water matrices play an important role in the photocatalytic degradation rate.

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