Construction of a Z-scheme heterojunction for high-efficiency visible-light-driven photocatalytic CO2 reduction
TL;DR: The Z-scheme heterojunction has a high separation efficiency of electron-hole pairs with strong redox ability and a wide light response range, which makes it a great opportunity for the conversion of CO2 to value-added chemicals as mentioned in this paper.
Abstract: The continuous growth of fossil fuel consumption and large amounts of CO2 emissions have caused global energy crisis and climate change. The employment of semiconductor photocatalysts to convert CO2 into value-added products has attracted extensive attention and research worldwide in recent years. However, it is difficult for a single-component semiconductor photocatalyst to achieve this goal efficiently due to its drawbacks, such as low quantum efficiency, limited surface area, limited number of active sites, the short lifetime of photogenerated carriers, poor long-term stability, and the weak redox ability of carriers. Fortunately, inspired by photosynthesis, the construction of an artificial Z-scheme heterojunction has brought a new dawn for the realization of this goal. The Z-scheme heterojunction has a high separation efficiency of electron-hole pairs with strong redox ability and a wide light response range. The abovementioned advantages make the Z-scheme heterojunction provide a great opportunity for the conversion of CO2 to value-added chemicals. This review concisely reports the progress of the Z-scheme heterojunction in the field of photocatalytic CO2 reduction in recent years, photocatalytic mechanism, choice of oxidation and reduction systems, strategies for improving efficiency, confirmation of the Z-scheme charge transport mechanism, problems and challenges, and the prospects for the future.
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TL;DR: In this article, a 2D/2D highly crystalline carbon nitride/δ-Bi2O3 (HCCN/BO) Z-scheme heterojunction photocatalyst was synthesized via a facile solvothermal strategy.
52 citations
TL;DR: In this paper , a 2D/2D highly crystalline carbon nitride/δ-Bi2O3 (HCCN/BO) Z-scheme heterojunction photocatalyst was synthesized via a facile solvothermal strategy.
52 citations
TL;DR: In this article, a series of ternary multi-heterojunction CdS/Bi20TiO32/Bi4Ti3O12 (CdSxBTC) photocatalysts were prepared by hydrothermal deposition of nanoparticles.
Abstract: Facile fabrication of visible light responsive multicomponent heterostructure photocatalysts with synergistic photoelectron migration is an effective approach with potential application in water remediation and renewable energy generation. In this study, a series of ternary multi-heterojunction CdS/Bi20TiO32/Bi4Ti3O12 (CdSxBTC) photocatalysts were prepared by hydrothermal deposition of CdS nanoparticles (15–25 nm) over one pot combustion synthesized Bi20TiO32/Bi4Ti3O12 (BTC) nanostructures. Comprehensive characterization of the ternary composites revealed enhanced optical absorption, high interfacial contact, fast electron channelization and a prolonged excited state life time. The CdSxBTC composite materials displayed enhanced photocatalytic activity for endosulfan degradation (kapp value 6–12 times greater than pure semiconductors) and water splitting reaction (H2 production rate 1890 μmolg−1h−1 and apparent conversion efficiency 19%). The cell viability -study disclosed non-cytotoxic nature of the treated endosulfan solution. A synergistic Type-I bridged coupled Z-scheme electron migration process accounted for robust radical generation ability (•O2− and •OH) and photocatalytic activity of the ternary composites.
45 citations
TL;DR: In this article , a series of ternary multi-heterojunction CdS/Bi 20 TiO 32 /Bi 4 Ti 3 O 12 (CdSxBTC) photocatalysts were prepared by hydrothermal deposition of nanoparticles (15-25 nm).
Abstract: Facile fabrication of visible light responsive multicomponent heterostructure photocatalysts with synergistic photoelectron migration is an effective approach with potential application in water remediation and renewable energy generation. In this study, a series of ternary multi-heterojunction CdS/Bi 20 TiO 32 /Bi 4 Ti 3 O 12 (CdSxBTC) photocatalysts were prepared by hydrothermal deposition of CdS nanoparticles (15–25 nm) over one pot combustion synthesized Bi 20 TiO 32 /Bi 4 Ti 3 O 12 (BTC) nanostructures. Comprehensive characterization of the ternary composites revealed enhanced optical absorption, high interfacial contact, fast electron channelization and a prolonged excited state life time. The CdSxBTC composite materials displayed enhanced photocatalytic activity for endosulfan degradation (k app value 6–12 times greater than pure semiconductors) and water splitting reaction (H 2 production rate 1890 μmolg −1 h −1 and apparent conversion efficiency 19%). The cell viability -study disclosed non-cytotoxic nature of the treated endosulfan solution. A synergistic Type-I bridged coupled Z-scheme electron migration process accounted for robust radical generation ability ( • O 2 − and • OH) and photocatalytic activity of the ternary composites. • A simple and rapid combustion route is devised for one step synthesis of Bi 20 TiO 32 /Bi 4 Ti 3 O 12 binary composite. • Hydrothermal deposition of CdS leads to the formation multi-heterojunction CdS/Bi 20 TiO 32 /Bi 4 Ti 3 O 12 ternary composite. • A synergistic Type-I bridged coupled Z-scheme electron migration explains robust generation of reactive oxygen species. • The ternary composites highly active for endosulfan degradation (0.03527 min −1 ) and H 2 production (1890 µmol g −1 h −1 ). • Cell viability study substantiates non-cytotoxic nature of the treated endosulfan solution and the photocatalyst.
45 citations
TL;DR: In this paper , a review of recent research advances about rational design of semiconductor surface for photocatalytic CO2 reduction reaction (CO2RR) is presented, where surface engineering strategies for improved CO2 adsorption, activation, and product selectivity are reviewed.
40 citations
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TL;DR: In this paper, the fundamental mechanism of heterogeneous photocatalysis, advantages, challenges and the design considerations of g-C3N4-based photocatalysts are summarized, including their crystal structural, surface phisicochemical, stability, optical, adsorption, electrochemical, photoelectrochemical and electronic properties.
2,132 citations
TL;DR: This review gives a concise overview of the all-solid-state Z-scheme photocatalytic systems, including their composition, construction, optimization and applications, which have a huge potential to solve the current energy and environmental crises facing the modern industrial development.
Abstract: The current rapid industrial development causes the serious energy and environmental crises. Photocatalyts provide a potential strategy to solve these problems because these materials not only can directly convert solar energy into usable or storable energy resources but also can decompose organic pollutants under solar-light irradiation. However, the aforementioned applications require photocatalysts with a wide absorption range, long-term stability, high charge-separation efficiency and strong redox ability. Unfortunately, it is often difficult for a single-component photocatalyst to simultaneously fulfill all these requirements. The artificial heterogeneous Z-scheme photocatalytic systems, mimicking the natural photosynthesis process, overcome the drawbacks of single-component photocatalysts and satisfy those aforementioned requirements. Such multi-task systems have been extensively investigated in the past decade. Especially, the all-solid-state Z-scheme photocatalytic systems without redox pair have been widely used in the water splitting, solar cells, degradation of pollutants and CO2 conversion, which have a huge potential to solve the current energy and environmental crises facing the modern industrial development. Thus, this review gives a concise overview of the all-solid-state Z-scheme photocatalytic systems, including their composition, construction, optimization and applications.
1,949 citations
TL;DR: This Perspective highlights several heterogeneous and molecular electrocatalysts for the reduction of CO2 and discusses the reaction pathways through which they form various products, including copper, a unique catalyst as it yields hydrocarbon products with acceptable efficiencies.
Abstract: The electrochemical reduction of CO2 has gained significant interest recently as it has the potential to trigger a sustainable solar-fuel-based economy. In this Perspective, we highlight several heterogeneous and molecular electrocatalysts for the reduction of CO2 and discuss the reaction pathways through which they form various products. Among those, copper is a unique catalyst as it yields hydrocarbon products, mostly methane, ethylene, and ethanol, with acceptable efficiencies. As a result, substantial effort has been invested to determine the special catalytic properties of copper and to elucidate the mechanism through which hydrocarbons are formed. These mechanistic insights, together with mechanistic insights of CO2 reduction on other metals and molecular complexes, can provide crucial guidelines for the design of future catalyst materials able to efficiently and selectively reduce CO2 to useful products.
1,396 citations
TL;DR: Various cocatalysts, such as the biomimetic, metal-based,Metal-free, and multifunctional ones, and their selectivity for CO2 photoreduction are summarized and discussed, along with the recent advances in this area.
Abstract: Photoreduction of CO2 into sustainable and green solar fuels is generally believed to be an appealing solution to simultaneously overcome both environmental problems and energy crisis. The low selectivity of challenging multi-electron CO2 photoreduction reactions makes it one of the holy grails in heterogeneous photocatalysis. This Review highlights the important roles of cocatalysts in selective photocatalytic CO2 reduction into solar fuels using semiconductor catalysts. A special emphasis in this review is placed on the key role, design considerations and modification strategies of cocatalysts for CO2 photoreduction. Various cocatalysts, such as the biomimetic, metal-based, metal-free, and multifunctional ones, and their selectivity for CO2 photoreduction are summarized and discussed, along with the recent advances in this area. This Review provides useful information for the design of highly selective cocatalysts for photo(electro)reduction and electroreduction of CO2 and complements the existing reviews on various semiconductor photocatalysts.
1,365 citations
TL;DR: In this article, a review describes recent advances in the fundamental understanding of CO2 photoreduction on the surface of heterogeneous catalysts and particularly provides an overview of enhancing the adsorption/activation of CO 2 molecules.
Abstract: Large amounts of anthropogenic CO2 emissions associated with increased fossil fuel consumption have led to global warming and an energy crisis. The photocatalytic reduction of CO2 into solar fuels such as methane or methanol is believed to be one of the best methods to address these two problems. In addition to light harvesting and charge separation, the adsorption/activation and reduction of CO2 on the surface of heterogeneous catalysts remain a scientifically critical challenge, which greatly limits the overall photoconversion efficiency and selectivity of CO2 reduction. This review describes recent advances in the fundamental understanding of CO2 photoreduction on the surface of heterogeneous catalysts and particularly provides an overview of enhancing the adsorption/activation of CO2 molecules. The reaction mechanism and pathways of CO2 reduction as well as their dependent factors are also analyzed and discussed, which is expected to enable an increase in the overall efficiency of CO2 reduction through minimizing the reaction barriers and controlling the selectivity towards the desired products. The challenges and perspectives of CO2 photoreduction over heterogeneous catalysts are presented as well.
1,315 citations