Photothermal Catalysis Research Articles

Visible light-regulated thermal catalytic selectivity induced by nonthermal effects over CuNi/CeO2

Solar-assisted photothermal catalysis is a fascinated picture of chemical and energy conversion. However, it is difficult to distinguish the nonthermal effects due to the thermal and nonthermal tend to exhibit similar experimental results. Here, we reported that the CuNi alloy deposited CeO2 (CuNi/CeO2) with visible light excited carriers at the interface can promote CO2 reduction in the photothermal catalysis. Impressively, the CuNi/CeO2 exhibit different product selectivities in the dark and visible light reactions, especially the light promoted the further hydrogenation to CH4 conversion. Detailed experiments reveal that the hot electron transfer between plasmon metal Cu and metal Ni under visible light excitation alters the pathway of thermal reduction while increasing surface hydroxyl and oxygen vacancies as CO2 trapping sites. The excessive H2 activation under visible irradiation induces the deep reduction of CO2 to CH4, instead of reverse water gas shift. Combining with in-situ DRIFTS, quasi-situ EPR, H2 pulse and DFT calculations, the nonthermal effects of CO2 reduction is proposed over CuNi/CeO2 with electrons transfer between Cu and Ni nanoparticles.

Enhanced toluene oxidation by photothermal synergetic catalysis on manganese oxide embedded with Pt single-atoms

The degradation of volatile organic compounds (VOCs) at low temperature remains a big challenge. Photothermal catalysis coupling the advantages of photocatalysis and thermocatalysis is promising to address this issue. However, there is still a long way to construct highly active catalysts and deeply understand the mechanism of photothermal catalysis. Herein, maganese oxide (MnO2)catalysts embedded with Pt single-atoms (0.11 wt% Pt) have achieved greatly enhanced toluene conversion of 95%, far surpassing most supported Pt photothermal catalysts. The excellent catalytic activity has been disclosed to derive from the synergetic effect oflight-driven thermocatalysis and photocatalysis. The light-driven thermocatalysis predominates and the strong electron transfer from Pt single-atoms to MnO2 improves the activity of surface lattice oxygen to boost the generation of benzoic acid and the mineralization of toluene. Meanwhile, in photocatalytic process, Pt single-atoms accelerate the generation of superoxide radicals (O2−), which facilitate the ring-opening and deep oxidation of toluene. This understanding on the photothermal synergetic mechanism will inspire the design of highly efficient catalysts for VOCs oxidation.

Local surface plasmon resonance promotion of photogenerated electrons to hot electrons for enhancing photothermal CO2 hydrogenation over Ni(OH)2/Ti3C2 catalysts

Although photothermal catalysis is currently used to enhance carbon dioxide (CO2) hydrogenation, it is challenging to gain an in-depth understanding of the enhancement involved in this process. Ni(OH)2/Ti3C2 (NiTC) photothermal catalysts were prepared using an acid–base etching–hydrothermal method. β-Ni(OH)2 was loaded on the surface of Ti3C2 and inserted between the layers to generate a built–in electric field (BIEF) at the interface of Ni(OH)2 and Ti3C2. The strong coupling between plasmonic Ti3C2 and Ni(OH)2 results in NiTC exhibiting surface plasmonic transverse electric resonance (TE) and transverse magnetic resonance (TM) waves, as well as the enhanced absorption peak. The local surface plasmon resonance (LSPR) effect occurs when Ti3C2 and Ni(OH)2 are excited by visible–near infrared light, while the spectral overlap of the two produces enhances the TM waves. The enhanced TM waves of Ti3C2 “pump” photogenerated electrons to transform them into hot electrons to replenish Ti3C2 via Landau damping and the BIEF. More hot electron generation enhances the photothermal CO2 conversion. The average photothermal CO2 conversion is 0.89 mmol·gcat.–1·h–1 over NiTC composite at 250 °C, 14 times that of Ti3C2.

The Mars-Van Krevelen cycle and non-noble metal Ni jointly promoting Z-scheme charge transfer: a study on the photothermal synergy effect applied in selectively oxidizing aromatic alcohols.

Photothermal catalysis is a promising method for selectively oxidizing organic compounds, effectively addressing the energy-intensive and low-selective processes of thermal catalysis, as well as the slow reaction rates of photocatalysis. In this study, a ternary photothermal catalyst, Ni/CeO2/CdS, was synthesized using a simple calcination and solvothermal method. The catalyst demonstrated remarkable improvement in reaction rates and achieved nearly 100% selectivity in converting benzyl alcohol to benzaldehyde through photothermal catalysis at normal pressure. The reaction rates were 5.9 times and 63 times higher than those of CdS and Ni/CeO2 individually. XPS analysis confirmed that the thermal catalysis followed the Mars-Van Krevelen (MVK) mechanism and also proved that photocatalysis facilitated the MVK cycle. Additionally, DFT calculations showed that Ni acted as an electron transfer channel, facilitating efficient Z-scheme charge transfer. The in situ infrared technique was used to dynamically monitor the reaction process and explain the high selectivity of the product. Furthermore, detailed explanations of photocatalysis, thermocatalysis, and photothermal synergistic catalysis were proposed based on the aforementioned characterization and theoretical calculations. This approach establishes a theoretical foundation for the development of efficient photothermal catalysts.

Polyoxometalate-based frameworks for photocatalysis and photothermal catalysis.

Polyoxometalate-based frameworks (POM-based frameworks) are extended structures assembled from metal-oxide cluster units and organic frameworks that simultaneously possess the virtues of POMs and frameworks. They have been attracting immense attention because of their diverse architectures and charming topologies and also due to their probable application prospects in the areas of catalysis, separation, and energy storage. In this review, the recent progress in POM-based frameworks including POM-based metal organic frameworks (PMOFs), POM-based covalent organic frameworks (PCOFs), and POM-based supramolecular frameworks (PSFs) is systematically summarized. The design and construction of a POM-based framework and its application in photocatalysis and photothermal catalysis are introduced, respectively. Finally, our brief outlooks on the current challenges and future development of POM-based frameworks for photocatalysis and photothermal catalysis are provided.

Laser-Induced Methanol Decomposition for Ultrafast Hydrogen Production

Methanol (CH3OH) is a liquid hydrogen (H2) source that effectively releases H2 and is convenient for transportation. Traditional thermocatalytic CH3OH reforming reaction is used to produce H2, but this process needs to undergo high reaction temperature (e.g., 200 °C) along with a catalyst and a large amount of carbon dioxide (CO2) emission. Although photocatalysis and photothermal catalysis under mild conditions are proposed to replace the traditional thermal catalysis to produce H2 from CH3OH, they still inevitably produce CO2 emissions that are detrimental to carbon neutrality. Here, we, for the first time, report an ultrafast and highly selective production of H2 without any catalysts and no CO2 emission from CH3OH by laser bubbling in liquid (LBL) at room temperature and atmospheric pressure. We demonstrate that a super high H2 yield rate of 33.41 mmol·h-1 with 94.26% selectivity is achieved upon the laser-driven process. This yield is 3 orders of magnitude higher than the best value reported for photocatalytic and photothermal catalytic H2 production from CH3OH to date. The energy conversion efficiency of laser light to H2 and CO can be up to 8.5%. We also establish that the far from thermodynamic equilibrium state with high temperature inside the laser-induced bubble and the kinetic process of rapid quenching of bubbles play crucial roles in H2 production upon LBL. Thermodynamically, the high temperature induced using laser in bubbles ensures fast and efficient release of H2 from CH3OH decomposition. Kinetically, rapidly quenching of laser-induced bubbles can inhibit reverse reaction and can keep the products in the initial stage, which guarantees high selectivity. This study presents a laser-driven ultrafast and highly selective production of H2 from CH3OH under normal conditions beyond catalytic chemistry.

Two-dimensional nanomaterials: synthesis and applications in photothermal catalysis.

Photothermal catalysis, as one of the emerging technologies with synergistic effects of photochemistry and thermochemistry, is highly attractive in the fields of environment and energy. Two-dimensional (2D) nanomaterials have received extensive attention toward photothermal catalysis because of their ultrathin layer structures, superior physical and optical properties, and high surface areas. These merits are beneficial for shortening the transfer distance of charge carriers, improving the efficiency of solar to thermal, and providing a great opportunity for the development of photothermal chemistry. In this review, we have summarized the state-of-art advances in various 2D nanomaterials with emphasis on the driving force and relevant mechanism of photothermal catalysis, including the involved three types, namely, localized surface plasmonic resonance (LSPR), nonradiative relaxation, and thermal vibrations of molecules. Moreover, the synthesis strategies of 2D materials and their photothermal applications in carbon dioxide (CO2) conversion, hydrogen (H2) production, volatile organic compounds (VOCs) degradation, and water (H2O) purification have been discussed in detail. Ultimately, the existing challenges and prospects of future development in the field are proposed. It is believed that this review will afford a great reference for the exploration of the high-efficiency 2D nanomaterials and their structure-activity relationship.

Photothermal catalytic C1 conversion on supported catalysts

Photothermal catalysis is a promising method for converting C1 feedstocks into valuable chemicals. This comprehensive review highlights the mechanism, design strategies for catalysts, and recent progress in photothermal catalytic C1 conversion.

Application of different molecular sieves in photothermal catalysis of Jatropha oil

Application of different molecular sieves in photothermal catalysis of Jatropha oil

Continuously Flow Photothermal Catalysis Efficiently CO2 Reduction Over S-Scheme 2D/0D Bi5 O7 I-OVs/Cd0.5 Zn0.5 S Heterojunction with Strong Interfacial Electric Field.

Using CO2 , water, and sunlight to produce solar fuel is a very attractive process, which can synchronously reduce carbon and convert solar energy into hydrocarbons. However, photocatalytic CO2 reduction is often limited by the low selectivity of reduction products and poor photocatalytic activity. In this study, S-scheme Bi5 O7 I-OVs/Cd0.5 Zn0.5 S (Bi5 O7 I-OVs/CZS-0.5) heterojunction with strong interfacial electric field (IEF) is prepared by in situ growth method. The performance of reduction CO2 to CO is studied by continuous flow photothermal catalytic (PTC) CO2 reduction platform. 12.5% Bi5 O7 I-OVs/CZS-0.5 shows excellent CO yield of 58.6µmolg-1 h-1 and selectivity of 98.4%, which are 35.1 times than that of CZS-0.5 under visible light. The charge transfer path of the S-scheme through theoretical calculation (DFT), in situ irradiation Kelvin probe force microscope (ISI-KPFM) and in situ irradiation X-ray photoelectron spectroscopy (ISI-XPS) analysis, is verified. The study can provide useful guidance and reference for improving activity by oxygen vacancy induced strong IEF and the development of a continuous flow PTC CO2 reduction system.

Photo‐Driven Hydrogen Production from Methanol and Water using Plasmonic Cu Nanoparticles Derived from Layered Double Hydroxides

AbstractMethanol steam reforming (MSR) is viewed as an important technology in the growth of a future hydrogen economy, with methanol serving as an easily transportable and storable liquid hydrogen carrier. However, the thermocatalytic MSR reaction is energy intensive as it requires high temperatures. Herein, a novel L‐Cu catalyst is successfully fabricated for photo‐driven MSR through reduction of CuAl layered double hydroxide (CuAl‐LDH) nanosheets. L‐Cu offers outstanding activity for the photothermal conversion of methanol and water to hydrogen (160.5 µmol gcat−1 s−1) under ultraviolet‐visible irradiation, with this rate being much higher than that achieved for L‐Cu at the same temperature in the dark. Characterization studies using X‐ray diffraction, X‐ray photoelectron spectroscopy, X‐ray absorption spectroscopy, and high‐resolution transmission electron microscopy determine that L‐Cu catalyst comprise Cu nanoparticles on an amorphous alumina support. Computational calculations reveale that Cu localized surface plasmon resonance effects promote the activation of H2O, thereby underpinning the remarkable hydrogen production rates achieved during photo‐driven MSR. This study introduces a novel photothermal strategy for hydrogen generation from methanol, demonstrating the enormous potential of photothermal catalysis in the chemical and energy sectors.

Near-Infrared-Induced Photothermal Enhanced Photocatalytic H2 Production for 3D/2D Heterojunctions of Snowflake-like CuS/g-C3N4 Nanosheets.

The conversion of solar power to hydrogen (H2) energy efficiently encounters some obstacles due to the lack of superior catalysts and efficient catalytic approaches. Herein, three-dimensional/two-dimensional (3D/2D) CuS/g-C3N4 photothermal catalysts were obtained via an easy, one-step hydrothermal method after pyrolysis. The favorable heterojunction interface for H2 production was constructed by snowflake-like CuS embedded in the graphite carbon nitride (g-C3N4) nanosheets, leading to the acceleration of charge transfer and separation, decrease of charge transfer distance, and perfect realization of photothermal effects (PTEs) induced by near-infrared (NIR) light. The 3D/2D CuS/g-C3N4 catalyst presents a topmost H2-production rate (1422 μmol h-1 g-1) under dual wavelength (420 + 850 nm) and a moderate H2-production rate under 420 nm, which are 12-fold and 9-fold higher than pure g-C3N4, respectively, owing to a strong action from PTEs induced by NIR. The feasible NIR-enhanced photothermal catalysis is expected to apply in multifarious heat-assisted photocatalysis processes by designing multifunctional composites with super PTE and photocatalytic capacity.

Systematic study of H2 production from photothermal reforming of α-cellulose over atomically thin Bi2MoO6

Photothermal reforming of biomass for hydrogen production is not only a low-carbon and environmentally friendly way to obtain hydrogen energy, but also a new strategy to achieve the utilization of waste resources. Due to the stable chemical properties of α-cellulose, the easy recombination of photogenerated carriers in photocatalysts, and the slow kinetics of hydrogen evolution, the catalytic conversion of biomass to hydrogen driven by sunlight remains a huge challenge. Herein, we report a new method for the conversion of α-cellulose to H2 by synergistic photothermal reforming over Bi2MoO6. Due to the unique atomically thin structure and more abundant oxygen vacancies, A-Bi2MoO6 has a narrow band gap, more negative conduction band and abundant hydrogen evolution sites. The material characterization reveals that the band gaps of A-Bi2MoO6 and N-Bi2MoO6 are 2.37 eV and 2.41 eV, respectively, and the conduction band edges are −0.33 eV and −0.03 eV, respectively. The DFT calculations show that the H atom obtains the ideal ΔGH0 (-0.65 eV) in the oxygen vacancy site. All these are beneficial to the production of H2. Therefore, the H2 yield produced by α-cellulose photothermal reforming over A-Bi2MoO6 was 214.63 μmol·gcat-1 after 4 h of reaction, which was 1.85 times higher than that of N-Bi2MoO6. Photothermal synergistic catalysis significantly increased the catalytic activity of A-Bi2MoO6, which was mainly attributed to the fact that temperature promoted the activation of some reactants, while light irradiation decreased the activation energy barrier of the reaction. Therefore, the H2 yield obtained by photothermal catalysis is higher than the sum of the H2 yield obtained by photocatalysis and the H2 yield obtained by thermocatalysis during the α-cellulose reforming reaction.

An efficient and universal solar interfacial photothermal reactor toward liquid phase oxidation

AbstractPhotothermal catalysis has attracted great attention owing to high solar energy utilization efficiency, and great progress has been achieved in gas‐phase catalysis. However, photothermal catalysis in liquid‐phase shows a limited performance, due to high specific heat capacity of liquid. Herein, an interfacial photothermal catalytic (IPC) strategy applying an IPC leaf was designed for liquid‐phase catalysis using benzyl alcohol oxidation as the model reaction. On even ground, the benzaldehyde generation rate (8.7 mmol gcat−1 h−1) of the IPC system with Ce‐doped MnO2 as photothermal catalyst was almost 4.8 times and 3 times of bulk photothermal catalysis and the relative bulk thermal catalysis. Experimental results proved that this excellent catalytic performance could be attributed to both the high temperature achieved and the enhanced lattice oxygen activity by solar irradiation. This IPC system also exhibited good universality and long‐term durability. Our work innovatively created a green strategy to obtain fine chemicals with only solar irradiation.

Mechanism and kinetic characteristics of photo-thermal dry reforming of methane on Pt/mesoporous-TiO2 catalyst

Dry reforming of methane (DRM) reaction under photo-thermal catalysis route have attracted more and more attentions due to its fast reaction rate and higher conversion compared with traditional thermal catalysis techniques. However, most of current researches were mainly focused on the development of new photo-thermal catalysts, while the kinetic characteristics of DRM reaction under photo-thermal conditions was seldomly studied and discussed. Aiming this point, the performances of a Pt/mesoporous-TiO2 catalyst were investigated under different reaction conditions (reaction temperature, light irradiation intensity and molar ratio of feed gases) in this paper. It was found that (1) Increasing the light intensity and reaction temperature possessed a positive effect on the DRM reaction, increasing the formation rates of two products and H2/CO ratio; (2) The intensification ratio of formation rates of light/dark condition would decrease with higher reaction temperature; (3) Under dark conditions, increasing the partial pressure of CO2 was not conducive to the progress of the DRM reaction; (4) With light irradiation, an appropriate increase in the partial pressure of CO2 would be beneficial to the progress of the DRM reaction and improve the formation rates of the products. To explain the variations of light-enhanced intensification ratios and values at different temperatures, a possible simple model of light-enhanced reaction mechanism was proposed, and the contribution of light to the DRM reaction was deeply discussed. Meanwhile, combined with in situ DRIFTS characterization, the effects of operating conditions on specific micro-steps of the reaction were determined carefully. The obtained conclusions are of great practical significance for the design, development and process parameter optimization of photo-thermal DRM reaction process.

Porous unsupported CuO nanoplates for efficient photothermal CO oxidation

It is a significant issue for environmental protection and industrial production to eliminate CO, a gas harmful to life and some important reaction sites. Real environmental conditions require catalytic CO oxidation to occur at relatively low temperature. Nowadays, photothermal catalysis has been exploited as a new way to achieve CO elimination, different from thermal catalysis. CuO, as cheap and abundant substitute for precious metals, is considered to have potential in photothermal catalysis. Oxygen vacancies (OV) and lattice oxygen (OL) activity are considered extremely crucial for oxide catalysts in CO oxidation, according to Mars−van Krevelen mechanism. Herein, porous CuO nanoplates with adjustable OV and OL activity were prepared by a facile method via controlling the morphology and phase composition of precursors. The light-off temperature (50% conversion) of the best sample obtained under the optimal conditions was ∼110 °C and an almost complete conversion was reached at ∼150 °C. It also achieved nearly 70% conversion under 6 standard Suns (6 kW cm−2 irradiation) and could work in infrared radiation (IR) regions, which could be attributed to the photo-induced thermal effect and activation effect. The simple synthesis and characterization provide a good example for the future photothermal catalysis.

Hierarchical porous metallic glass with strong broadband absorption and photothermal conversion performance for solar steam generation

The development of a strong light absorption absorber with a facile preparation process are crucial for some photothermal conversion applications, such as solar steam generation, photothermal catalysis and detectors. Here, a hierarchical structure based on microporous surface equipped with nanoporous layer is ingeniously designed and fabricated benefiting from the unique thermoplastic forming ability of metallic glasses by using the soluble clusters as template in less than 30 s. The presence of hierarchical porous structures induces multiple reflection of light and excites the plasmonic behavior of surface, achieving over 90% light absorption in the 380–20 µm wavelength range and the broad light incident angle from 0° to 70°, resulting in a remarkable photothermal conversion performance. Compared to conventional and existing absorber, the innovatively designed and fabricated metallic surface offers outstanding advantages in terms of light absorption range, heating rate and maximum temperature rise. Afterwards, the hierarchical porous structures for solar steam generation shows an evaporation efficiency of up to 94.2% and evaporation rate of 1.72 kg m−2 h−1 at 1 kW m−2. The design of unprecedented structure on metallic glass opens up a new strategy for solar energy harvesting, water treatment and other related fields.

MxCo3O4/g-C3N4 Derived from Bimetallic MOFs/g-C3N4 Composites for Styrene Epoxidation by Synergistic Photothermal Catalysis

MxCo3O4/g-C3N4 Derived from Bimetallic MOFs/g-C3N4 Composites for Styrene Epoxidation by Synergistic Photothermal Catalysis

Uniting Heat and Light in Heterogeneous CO2 Photocatalysis: Optochemical Materials and Reactor Engineering

ConspectusThe rapid increase in atmospheric CO2 concentration (∼420 ppm) has become one of the significant issues threatening human survival. As an effective measure to solve this major problem, renewable energy-powered catalytic CO2 conversion technologies have received vast attention in both academia and industry. Among these techniques, photothermal catalysis is a rising star with promising potential for CO2 conversion even under milder conditions. Indium oxide was among the first to be used in photothermal CO2 catalysis, and through its various forms, stoichiometries, and surface chemistry, it has become one of the most well-studied photothermal catalyst systems. Indium oxide is a highly tunable semiconductor for CO2 photocatalysis, which can be driven by both light photochemically and heat photothermally, thereby serving as an archetype for understanding how to optimize its performance for storing solar as chemical energy, through creative materials chemistry.Our solar fuel cluster discovered photothermal CO2 catalysis over indium oxide in 2014 and has long been committed to the study of this field. Photothermal catalysis by semiconductors like indium oxide can be deconstructed into three key processes: photochemistry, thermochemistry, and surface chemistry. To be specific, photoexcited electron–hole pairs can enable redox and acid–base surface chemical reactions. Phonons and plasmons can drive these reactions photothermally. Surface active sites, such as surface frustrated Lewis pairs and oxygen vacancies, can amplify product activity and selectivity. Designer synergism between all of these effects ultimately determines the overall performance metrics of photothermal CO2 catalysis. Thus, to design and optimize a photothermal catalyst, the three aforementioned key processes should be considered synergistically.In this Account, indium oxide-based catalysts are selected as an archetype to introduce the process of photothermal CO2 catalysis and the advancements of indium oxide-based catalysts mainly from our solar fuel cluster are summarized. In detail, the strategies of material design are introduced systematically with the three key processes: photochemistry, thermochemistry, and surface chemistry. Moreover, a foreseeable future of the emerging field of optochemical engineering of photothermal catalysis, ranging from potential reactions to reactor design, is included as the perspective as well. In other words, this Account is dedicated to exploring how chemically tailored indium oxide-based catalyst has served as a platform material for understanding photothermal CO2 catalysis and how this know-how is enabling the design of high quantum efficiency photocatalysts and photoreactors. A comprehensive understanding of these points is the key to the development of the emerging field of optochemical materials and reactor engineering of heterogeneous CO2 photocatalysis.

Photothermal Catalytic Polyester Upcycling over Cobalt Single‐Site Catalyst

AbstractPhotothermal catalytic conversion of waste plastics into fuels and/or feedstocks using renewable solar energy can achieve solar‐to‐chemical conversion, resource sustainability, and environmental remediation simultaneously. However, the construction of photothermal catalysts with strong light absorption and high catalytic activity remains a great challenge. In this work, integrated cobalt single‐site catalysts (Co SSCs), coupled with strong photothermal conversion, high catalytic activity, and stability, are employed to catalyze the glycolysis of polyesters. The unique coordination‐unsaturated CoO5 single‐site can coordinate with the carbonyl groups in polyester, thus boosting the nucleophilic addition elimination processes. As a result, the space‐time yield of Co SSCs is an order of magnitude higher than that of general catalysts. In addition, the polyethylene terephthalate (PET) conversion and bis(2‐hydroxyethyl) terephthalate yield in photothermal catalysis are 5.4 and 6.6 times higher than those of thermal catalysis under the same conditions, which are contributed by the localized heating effect. Technical economic analysis shows that the recycling of 105 tons of waste PET by photothermal catalysis consumes 146.4 GW·h electrical energy and misses 7.44 × 104 tons of CO2 emission. Therefore, a high‐efficient photothermal catalytic plastic recycling system is of great significance for waste plastic valorization.