2D/1D MoS₂/TiO₂ Heterostructure Photocatalyst with a Switchable CO₂ Reduction Product

Abstract

climate change. [1] Thus, there is an acute need to develop green technologies for converting solar energy into pure chemical energy that could reduce the greenhouse effect and alleviates the global energy crunch. [2] Photocatalytic CO 2 reduction into CO or economic hydrocarbon fuel like methane (CH 4 ), as well as photoelectrochemical water splitting into a zerocarbon emission fuel (H 2 production) are promising ways to convert and store solar energy. [2c,3] Semiconductor nanoparticles have gained interest in the fields of photocatalysis, water splitting, and energy conservation and conversion. [2b,3c,4] Among them, titanium oxide has played a significant role in efficiently mitigating air and water pollution problems due to its excellent optoelectronic properties and long-term photostability. [2c,4-7] Yet, the inappropriate large energy band gap, high electron-hole recombination, and unfavorably low solar light consumption have hindered the photoconversion efficiency of the pristine TiO 2 semiconductor. [2c,4b,8] Heterostructuring TiO 2 with an appropriate semiconductor is an operative approach to overcome its drawbacks and construct an efficient photocatalyst. [2c,4a,8] MoS 2 is an appealing semiconductor for fabricating heterostructured Regulating the transfer pathway of charge carriers in heterostructure photocatalysts is of great importance for selective CO 2 photoreduction. Herein, the charge transfer pathway and in turn the redox potential succeeded to regulate in 2D MoS 2 /1D TiO 2 heterostructure by varying the light wavelength range. Several in situ measurements and experiments confirm that charge transfer follows either an S-scheme mechanism under simulated solar irradiation or a heterojunction approach under visible light illumination, elucidating the switchable property of the MoS 2 /TiO 2 heterostructure. Replacing the simulated sunlight irradiation with the visible light illumination switches the photocatalytic CO 2 reduction product from CO to CH 4.13 CO 2 isotope labeling confirms that CO 2 is the source of carbon for CH 4 and CO products. The photo electrochemical H 2 generation further supports the switching property of MoS 2 /TiO 2 . Unlike previous studies, density functional theory calculations are used to investigate the band structure of Van der Waals MoS 2 /TiO 2 S scheme after contact, allowing to propose accurate charge transfer pathways, in which the theoretical results are well matched with the experimental results. This work opens the opportunity to develop photocatalysts with switchable charge transport and tunable redox potential for selective artificial photosynthesis.

Fluorinated-TiO2/Mn0.2Cd0.8S S-Scheme Heterojunction with Rich Sulfur Vacancies for Photocatalytic Hydrogen Production

“…Aside from the absorption edge, the photocatalysts’ valence band (VB) and conduction band (CB) potentials are important variables influencing photocatalytic activity. The band gap energies of pure F-TiO 2 and MCS are estimated via the following formula , α h ν = A false( h ν − E g false) n / 2 where α, hv , A , and E g represent the adsorption coefficient, photon energy, a constant of proportionality, and band gap energies, respectively. Additionally, according to the different types of semiconductors, n represents different values.…”

Magnesium Bismuth Ferrite Nitrogen-Doped Carbon Nanomagnetic Perovskite: Synthesis and Characterization as a High-Performance Electrode in a Supercapacitor for Energy Storage

“…The energy storage and conversion properties of perovskite-type (ABX 3 ) materials are particularly advantageous among others nanoheterostructures. Moreover, in regard to fossil fuel depletion and climate change, much attention has been invested in offering innovative renewable energy storage systems . The hunt for affordable, highly effective electrode materials for use in upcoming energy applications is a research hotspot.…”

Synergistic Trimetallic Nanocomposites as Visible–NIR–Sunlight-Driven Photocatalysts for Efficient Artificial Photosynthesis

“…Carbon dioxide (CO 2 ) is the major culprit for global warming, and the CO 2 emissions increased by ∼1.0% in 2022, which corresponded to the highest ever CO 2 emission (36.6 billion tonnes). , Hence, there is an urgent need to cut down CO 2 emissions to prevent the serious effects on environmental change (to keep the global warming change less than 2 °C) . The photocatalytic conversion of CO 2 to useful hydrocarbons using the efficient artificial photosynthesis technique is the practical method to produce green solar fuels and overcome the adverse changes in climate. − Semiconductors, viz., TiO 2 , , BiVO 4 , MOFs, chromates, and metal halide perovskites have been used for CO 2 photoconversion.…”