1D/2D TiO₂/MoS₂ Hybrid Nanostructures for Enhanced Photocatalytic CO₂ Reduction

Abstract

fields. Photocatalytic CO 2 reduction over photocatalysts is a promising approach to overcome these two crises. [1][2][3][4][5][6][7] This approach can recycle CO 2 back to rene wable fuels by using solar energy which is green and inexhaustible. [8][9][10][11][12][13][14] TiO 2 has widely been utilized for photocata lytic CO 2 reduction owing to its stability, nontoxicity, and earth abundance, [15][16][17][18][19][20] but suffers from rapid recombination of electronhole pairs [21][22][23] and large bandgap. [24][25][26] Some strategies were developed to improve the photocata lytic performance including noble metal deposition, [27][28][29][30] doping, [31,32] surface photosensitization, [33,34] and constructing heterojunctions. [35][36][37][38][39] Among them, coupling TiO 2 with narrowband semi conductors is regarded as an efficient way to enhance separation of electron-hole pairs and promote light absorption, such as CdSe, [40,41] CdTe, [42,43] MoS 2 , [44][45][46][47] and CdS. [48][49][50] As a family member of the 2D materials family, transition metal dichal cogenides (TMDs) have recently attracted much attention owing to their remark able optical and electronic properties. As a typical TMD material, MoS 2 has been the subject of a large amount of research in electronic devices, electrochemistry and photocatalysis. [51][52][53][54] MoS 2 has a narrow bandgap around 1.2 eV and its conduction band (CB) level can be facilely adjusted by altering its number of layers due to quantum confinement, [55,56] which makes MoS 2 a highly promising sensitizer for photocatalysis processes, such as hydrogen evolution and CO 2 reduction. Recently, TiO 2 /MoS 2 has been reported for photocatalytic oxidation, photocatalytic H 2 pro duction, and photovoltaics, however, photocatalytic CO 2 con version to solar fuels over fibrous TiO 2 /MoS 2 has barely been reported.Herein, 1D/2D TiO 2 /MoS 2 hybrid nanofibers have been prepared by in situ growing MoS 2 nanosheets onto TiO 2 nanofibers. Such hybrid nanofibers exhibit abundantly porous structure, improved light absorption, and enhanced charge separation over photoexcitation. Therefore, the 1D/2D hybrid shows a superior photocatalytic activity for photoreducing CO 2 into hydrocarbons under UV-visible light irradiation. The synergistic effect of MoS 2 deposition onto TiO 2 fiber is analyzed and discussed in detail to understand the photocatalytic mechanism.Photocatalytic reduction of CO 2 into solar fuels is recognized an attractive approach to solve the environmental and energy crisis. MoS 2 , a type of 2D transition metal dichalcogenides, has attracted significant attention in photoelectronics, sensors and photo/electrocatalytic water splitting owing to its remarkable properties. Nevertheless, to date, MoS 2 is barely used as (co)catalyst for CO 2 photoreduction. Herein, novel 1D/2D TiO 2 /MoS 2 nanostructured hybrid with TiO 2 fibers covered by MoS 2 nanosheets by hydrothermal transformation method is fabricated. The MoS 2 sheet arrays show a lateral size of ≈80 nm and a thickness...

S‐Scheme Heterojunction TiO2/CdS Nanocomposite Nanofiber as H2‐Production Photocatalyst

“…Several studies showed that TiO 2 and TiO 2 ‐based materials have great application potential and inestimable value as photocatalysts . However, they still suffer from inferior solar light harvesting, low quantum efficiency (QE), low solar energy utilization, and rapid recombination of electron‐hole pairs …”

Photocatalytic CO2 Reduction and Thermal CO Oxidation to CO2 over Cu/Ni-loaded TiO2 Photo and Thermal Catalysts

“…This is attributed to the 4+ oxidation state of TiO 2 [12,15]. Two O 1s XPS peaks were observed at 530.2 and 532.0 eV, mainly due to lattice oxygen (O 2-) of TiO 2 and other surface oxygen species (e.g., OH and H 2 O) species, respectively [12,15].…”

“…To satisfy increasing demand, considerable effort has been devoted to the designing of new catalysts with higher catalytic performance [1,[7][8][9]. Among various strategies, guest transition metal doping/loading of a host metal oxide has been extensively employed [1,7,[10][11][12][13]. For recycling energy production using CO 2 reduction, Ola and Maroto-Vale loaded Cr, V, and Co onto honeycomb monolithic TiO 2 structures, tested vaporphase CO 2 photoreduction, and observed CH 4 and acetaldehyde production rates of 4.87 and 11.13 μmol g −1 h −1 , respectively, for 0.5 wt% V TiO 2 monoliths [9].…”

“…Xu et al reported 1D/2D TiO 2 /MoS 2 hybrid nanostructures prepared using the hydrothermal transformation method. They reported that CH 4 and CH 3 OH yields reached up to 2.86 and 2.55 μmol g −1 h −1 , respectively, for photocatalytic CO 2 reduction over 10 % MoS 2 /TiO 2 [12]. Bare TiO 2 fibers were reported to show only CH 3 OH as a reduction product with a yield of 0.72 μmol g −1 h −1 .…”

One‐dimensional and two‐dimensional synergized nanostructures for high‐performing energy storage and conversion

“…During the photocatalytic reaction, the well‐distributed TiO 2 shell was photoexcited to generate photoinduced electrons and holes, while the CNFs core facilitated the charges separation . Similarly, 1D/2D TiO 2 /MoS 2 hybrid nanofibers were made by in situ growth of MoS 2 nanosheets onto TiO 2 nanofibers, which exhibited abundantly porous structure, improved light absorption, and enhanced charge separation over photoexcitation . Herein, photonic nanostructures will not be discussed in detail, which can be referred to several existing reviews or articles …”