Photothermal Conversion Research Articles

NIR Absorbing Organic Chromophores Combination with NSAIDs for Remodeling of the Inflammatory Microenvironment to Amplify Tumor Ferroptosis-Photothermal Synergistic Therapy.

Photothermal therapy has emerged as a promising approach for cancer treatment, which can cause ferroptosis to enhance immunotherapeutic efficacy. However, excessively generated immunogenicity will induce serious inflammatory response syndrome, resulting in a discounted therapeutic effect. Herein, a kind of NIR absorption small organic chromophore nanoparticles (TTHM NPs) with high photothermal conversion efficiency (68.33%) is developed, which can induce mitochondria dysfunction, generate mitochondrial superoxide, and following ferroptosis. TTHM NPs-based photothermal therapy is combined with Sulfasalazine (SUZ), a kind of nonsteroidal anti-inflammatory drugs, to weaken inflammation and promote ferroptosis through suppressing glutamate/cystine (Glu/Cys) antiporter system Xc- (xCT). Additionally, the combination of SUZ with PTT can induce immunogenic cell death (ICD), followed by promoting the maturation of DCs and the attraction of CD8+ T cell, which will secrete IFN-γ and trigger self-amplified ferroptosis via inhibiting xCT and simulating Acyl-CoA synthetase long-chain family member 4 (ACSL4). Moreover, the in vivo results demonstrate that this combination therapy can suppress the expression of inflammatory factors, enhance dendritic cell activation, facilitate T-cell infiltration, and realize effective thermal elimination of primary tumors and distant tumors. In general, this work provides an excellent example of combined medication and stimulates new thinking about onco-therapy and inflammatory response.

Semiconducting Polymers Based on Asymmetric Thiadiazoloquinoxaline for Augmented In Vivo NIR-II Photoacoustic Imaging.

A photoacoustic (PA) imaging technique using the second near-infrared (NIR-II) window has attracted more and more attention because of its merits of deeper penetration depth and higher signal-to-noise (S/N) ratio than that using the first near-infrared (NIR-I) one. However, the design and development of high-performance PA imaging contrast agents in the NIR-II window is still a challenge. A semiconducting polymer, constructed by asymmetric units, exhibits regiorandom characteristics that effectively increase the distortion of the backbone. This increase in the degree of twist can regulate the twisted intramolecular charge transfer (TICT) effect, resulting in an enhancement of the PA signal. In this paper, an asymmetric structural acceptor strategy is developed to improve the PA signals of the resulting semiconducting polymer (PATQ-MP) in the NIR-II window with improved brightness, higher S/N ratio, and better photothermal conversion efficiency compared to polymers with the same main-chain structure containing a symmetric acceptor. DFT analysis showed that PATQ-MP containing an asymmetric acceptor monomer had a larger dihedral angle, which effectively improved the PA signal intensity by enhancing the TICT effect. The PEG-encapsulated PATQ-MP nanoparticles exhibit promising performance in the PA imaging of mouse tumors in vivo, demonstrating the clear identification of microvessels as small as 100 μm along with rapid metabolism within a span of 5 h. Therefore, this work provides a unique molecular design strategy for improving the signal intensity of PA imaging in the NIR-II window.

Comparative experimental study on photothermal conversion and shape memory properties of MF-based flexible composite phase change materials loaded with carbon nanotubes and polydopamine

Efficient use of solar energy can effectively alleviate the problem of energy shortages. Currently, extensive researches have been carried out on photothermal conversion materials. However, factors such as photothermal conversion and thermal conductivity limit the practical implementation of photothermal materials. In this research, a novel flexible composite phase change material (CPCM) with melamine foam (MF) as the supporting skeleton, carbon nanotube (MWCNT)/polydopamine (PDA) as the light-absorbing coating and polyethylene glycol (PEG) as the energy storage material was successfully prepared. The results show that the MF-based CPCMs have good shape stability with a leakage of only 0.9 %, and high phase change enthalpies, the melting enthalpy was above 172.0 J/g. In addition, the thermal conductivity was improved due to the introduction of light-absorbing coatings into the CPCMs. Compared with MF/PEG, MWCNT/MF/PEG, and PDA/MF/PEG, MWCNT/PDA/MF/PEG were improved by 35.21 %, 8.6 % and 29.46 %, respectively. Finally, the average charging efficiency of MWCNT/PDA/MF/PEG is 96.26 %, which is 62.33 % and 20.1 % higher than that of MWCNT/MF/PEG and PDA/MF/PEG respectively, indicating that MWCNT and PDA nanofillers played a synergistic role in enhancing the performance of CPCMs. This study provides new and innovative ways for the design of photothermal materials.

A graphene-CuNWs@PAMPS mixed aerogel for composite phase change materials with high thermal conductivity and excellent solar-thermal to electrical conversion

Phase change materials could store and release heat energy through phase change. However, the shortcomings of low thermal conductivity in the photothermal conversion process and easy leakage in the solid-liquid conversion seriously hinder the application of heat energy utilization. Graphene had high thermal conductivity, and it was an ideal material for improving the solar absorption, solar energy conversion and thermal conductivity of phase change materials. In this paper, a graphene aerogel composed of copper nanowires (CuNWs)/2-acrylamide-2-methylpropanesulfonic acid (AMPS) was designed. The thermal conductivity and shape stability of phase change materials for solar-thermal-electrical conversion applications were enhanced by composite CuNWs. Furthermore, PAMPS was coated on the surface of copper nanowires to avoid the oxidation of copper nanowires, and the sulfonic acid group of PAMPS was used to induce CuNWs to disperse uniformLy on the graphene sheets, which further constructed a good conductive network. After vacuum impregnation of PW, the best thermal conductivity phase change composite (PW-CuNWs@PAMPS-GA(1:1)) was obtained. The PCC loaded with CuNWs with the same graphene content achieved a thermal conductivity of 1.46 W/(m·K) and a high latent heat of 206.8 J/g. The latent heat retention rate was as high as 99.57 %. The photothermal conversion efficiency of PW-CuNWs@PAMPS-GA(1:1) was remarkable at 96.4 %. Due to its excellent solar-thermal-electrical conversion efficiency, the output voltage and output current were 800.8 mV and 85.8 mA, respectively, at a solar analog intensity of 5 kW/m2. Even after the sunlight was stopped, the voltage output could be maintained for a while by releasing the heat energy stored in the phase change composite.

In situ Photoactivated Antibacterial and Antioxidant Composite Materials to Promote Bone Repair.

Trauma and tumor removal usually cause bone defects; in addition, the related postoperative infection also should be carefully considered in clinical. In this study, we first prepared polylactic acid (PLLA) composite fibers containing CeO2 by electrospinning technology. Then, the PLLA/ CeO2@PDA /Ag composite materials were successfully prepared by reducing Ag+ to AgNPs coating in situ and binding AgNPs to the materials surface by mussel structure-liked polydopamine (PDA). In the materials, Ag+ can be slowly released in simulated body fluids. Based on the photothermal performance of AgNPs, the photothermal conversion efficiency of the materials were 21%, under NIR 808nm illumination. The effective photothermal conversion can help materials fighting with E. coli and S. aureus in 3 hours, with an antibacterial rate of 100%. Additionally, the sustained Ag+ release contribute to the antibacterial in long term. Meanwhile, the materials can mimic the bio-behavior of superoxide dismutase (SOD) and catalase (CAT) in decreasing the singlet oxygen level and removing the excess reactive oxygen species (ROS). Furthermore, the materials were beneficial for cell proliferation and osteogenic differentiation in vitro. In this study, we successfully constructed a promising bone-regenerated material with high photothermal conversion efficiency and antibacterial and anti-oxidation properties. This article is protected by copyright. All rights reserved.

RGOs-AgNPs/PVA composite sponges for efficient solar saltwater evaporation

With an increasing demand for seawater desalination, fabricating photothermal materials with low cost, high photothermal conversion efficiency, and excellent mechanical stability is necessary but remains challenging. In this work, reduced graphene oxide nanosheets (RGOs) and silver nanoparticles (AgNPs) doped polyvinyl alcohol (PVA) sponges (RGOs-AgNPs/PVA) are fabricated by the mechanical foaming and impregnation reduction method, which combine the flexible porous structure of PVA sponges with the photothermal properties of RGOs-AgNPs. The incorporation of RGOs-AgNPs enhances the surficial hydrophobicity and reduces the accumulation of water on the surface, and the photothermal synergistic effect of RGOs-AgNPs enhances the water evaporation rate. The results showed that the evaporation rate of RGOs-AgNPs/PVA was 2.09 kg m−2 h−1 and the photothermal conversion efficiency was 94.2 % under standard sunlight intensity of 1 sun (1.0 kW m−2). Furthermore, the long-term stability and effective desalination capability of the RGOs-AgNPs/PVA solar evaporation device offer a potential opportunity for massive seawater desalination. Therefore, this work shows the prospect of combining flexible porous sponges with photothermal materials for practical solar evaporation.

Highly flexible composite phase-change material PA-EG-AgNPs achieved through self-assembly of nano-silver for enhanced photothermal performance

This study presents an innovative composite phase-change material (cPCM) based on paraffin-expanded graphite (PA-EG), where AgNPs self-assemble onto the PA-EG surface. In comparison with the base material, the resulting composite, PA-EG12Ag-G, achieves a notably elevated thermal conductivity of 2.987 W/(m·K), emphasizing its superior heat conduction. Remarkably, the photothermal conversion efficiency sees a significant boost of 20.1 %, underlining its enhanced capacity for converting light to heat, attributed to the surface plasmon resonance of AgNPs. The cPCM also features a substantial phase change enthalpy of 130.5 J/g, ensuring exceptional heat storage capability. With a phase transition temperature of 46.3 °C, it gives multiple-choice for applications. Moreover, the material maintains outstanding room-temperature flexibility, making it being well-suited for practical use, such as a thermal management or solar thermal energy storage. The improvement in photothermal efficiency, facilitated by the surface plasmon resonance of AgNPs, adds a novel dimension to the material's capabilities, enhancing its potential for diverse applications.

PEGylated chitosan-coated nanophotosensitizers for effective cancer treatment by photothermal-photodynamic therapy combined with glutathione depletion

The combination of photothermal therapy (PTT) and photodynamic therapy (PDT) has emerged as a promising strategy for cancer treatment. However, the poor photostability and photothermal conversion efficiency (PCE) of organic small-molecule photosensitizers, and the intracellular glutathione (GSH)-mediated singlet oxygen scavenging largely decline the antitumor efficacy of PTT and PDT. Herein, a versatile nanophotosensitizer (NPS) system is developed by ingenious incorporation of indocyanine green (ICG) into the PEGylated chitosan (PEG-CS)-coated polydopamine (PDA) nanoparticles via multiple π-π stacking, hydrophobic and electrostatic interactions. The PEG-CS-covered NPS showed prominent colloidal and photothermal stability as well as high PCE (ca 62.8 %). Meanwhile, the Michael addition between NPS and GSH can consume GSH, thus reducing the GSH-induced singlet oxygen scavenging. After being internalized by CT26 cells, the NPS under near-infrared laser irradiation produced massive singlet oxygen with the aid of thermo-enhanced intracellular GSH depletion to elicit mitochondrial damage and lipid peroxide formation, thus leading to ferroptosis and apoptosis. Importantly, the combined PTT and PDT delivered by NPS effectively inhibited CT26 tumor growth in vivo by light-activated intense hyperthermia and redox homeostasis disturbance. Overall, this work presents a new tactic of boosting antitumor potency of ICG-mediated phototherapy by PEG-CS-covered NPS.

Near-infrared laser induced direct ignition of 4,4′,5,5′-tetranitro-1H,1′H-[2,2′-biimidazole]-1,1′-diamine by constructing diverse crystal structures

Although laser ignition is considered to be one of the most promising ways to detonate energetic materials due to its high safety and reliability, it is still a challenge to achieve direct ignition of energetic materials by a laser with low-power and near-infrared (NIR) band. In this paper, a molecular self-assembly strategy based on recrystallization was utilized to prepare 4,4′,5,5′-tetranitro-1H,1′H-[2,2′-biimidazole]-1,1′-diamine (DATNBI) crystals with various micro-nano structures. The characterization results suggest that DATNBI crystals with different degrees of roughness and defects by the induction of solvents and surfactants. The crystal defects can not only bring about the enhancement of light absorption of DATNBI in NIR band, but also advance its thermal decomposition, providing reliable support for direct laser ignition of DATNBI profit from the hot spot ignition theory. Combined with density functional theory, it is speculated that electrons of defect states achieve electron-hole recombination by laser radiation, thereby enhancing photothermal conversion. Compared with raw DATNBI, DATNBI crystals with rough surface and abundant defects can be directly ignited by a NIR laser and exhibits self-sustainable combustion. In summary, a direct NIR laser-ignitable energetic material has been prepared via appropriate crystal structure design.

Facile construction of gold- and BODIPY-coordinated liposomal nanocomplexes for enhanced photothermal therapy of cancer

Photothermal therapy (PTT) has attracted extensive attention in cancer treatment because of its advantages of non-invasive and few side effects. Gold nanoparticles and boron-fluorine-dipyrrole (BODIPY) dye have been used as photothermal agents (PTAs), but they have problems such as easy aggregation, poor water solubility and low photothermal conversion efficiency. In this work, we used conventional liposomes for in situ generation of small gold nanoparticles and sequentially loading BODIPY to overcome the drawbacks of the two PTAs and simultaneously realize enhanced PTT. Gold- and BODIPY-coordinated liposomal nanocomplexes LAB with small gold nanoparticles adsorbed on the surface and BODIPY entrapped inside showed uniform size of about 100 nm with good stability. LAB demonstrated laser-responsive drug release property, good cellular uptake efficiency and tumor accumulation ability. After laser irradiation, LAB can exert enhanced PTT in cancer cell lines by reducing mitochondrial membrane potential and increase intracellular reactive oxygen species level to promote cell apoptosis. In tumor-bearing mice, LAB showed fantastic tumor inhibition effect with good biosafety. This work provides a convenient method to develop PTA combinations for enhanced PTT, which could lay the foundation for the green construction of new PTAs for PTT by employing clinically used formulations and PTAs.

Self-floating and long-term stable Ti3C2TX/polyurethane composite membranes with highly efficient photothermal conversion performances for multiple applications

Self-floating and long-term stable Ti3C2TX/polyurethane composite membranes with highly efficient photothermal conversion performances for multiple applications

Vacancy-driven High-performance Metabolic Assay for Diagnosis and Therapeutic Evaluation of Depression.

Depression is one of the most common mental illnesses and is a well-known risk factor for suicide, characterized by low overall efficacy (< 50%) and high relapse rate (40%). A rapid and objective approach for screening and prognosis of depression is highly desirable but still awaits further development. Herein, we present a high-performance metabolite-based assay to aid the diagnosis and therapeutic evaluation of depression by developing a vacancy-engineered cobalt oxide (Vo-Co3O4) assisted laser desorption/ionization mass spectrometer platform. The nanoparticles with optimal vacancy achieve a signal enhancement (up to 20 folds than the commercialized products), characterized by favorable charge transfer and increased photothermal conversion. The optimized Vo-Co3O4 allows for a direct and robust record of plasma metabolic fingerprints (PMFs). Through machine learning of PMFs, high-performance depression diagnosis is achieved, with the areas under the curve (AUC) of 0.941-0.980 and an accuracy of over 92%. Further, a simplified diagnostic panel for depression is established, with a desirable AUC value of 0.933. Finally, we quantify proline levels in a follow-up cohort of depressive patients, highlighting the potential of metabolite quantification in the therapeutic evaluation of depression. Our work promotes the progression of advanced matrixes and brings insights into the management of depression. This article is protected by copyright. All rights reserved.

Efficient cleanup of highly viscous spilled oil using a fast solar-heating and super hydrophobic sponge

A solar-heating sponge, in which the polypyrrole (PPy) coating plays the role of photothermal converter and carbon nanotubes (CNTs) act as the thermal conductor, was fabricated. The sponge can effectively convert sunlight into heat and fast conduct heat so that the temperature can rise to 80 °C within 30s under 1 sun irradiation. Besides, the temperatures of the other parts rise synchronously with the top surface, unlike most reported sponges which had temperature differences between different parts. This advantage can avoid the decrease of diffusion rate of the oil in application. The sponge also exhibits super hydrophobility with a high water contact angle of 151.2°. The excellent solar-heating ability and hydrophobility make the sponge an efficient viscous oil adsorbent. The sponge can continuously and rapidly remove the spilled oil under solar irradiation. The coating composed of interconnected PPy nanosheets is firmly fixed on the surface of the elastic matrix via multiple H bonds. After 10 adsorption-desorption cycles, the adsorption capacity still maintains 97.2%, without any change in hydrophobility. These advantages including fast solar-heating, super hydrophobility and high regenerability demonstrate that the sponge has great potential in oil spill treatment, especially highly viscous oils.

Stability, Thermophysical, Optical and Photothermal Properties of ZnO Nanofluids with Added Anionic/Cationic Mixed Surfactants

Abstract Metal oxide nanofluid is a new type of heat transfer medium with good thermal performance, which can be used to improve the heat collection and photothermal conversion performance of the collector. The development of new nanofluids with excellent stability, thermophysical and photothermal properties is very important for solar thermal utilization. In this paper, the ZnO nanofluids with SDS/CTAB mixed surfactants were prepared by two-step method. Their stability, thermophysical, optical and photothermal properties were studied based on experimental data. Then, the optimum concentration and preparation conditions of the proposed ZnO nanofluid adding SDS/CTAB with good photothermal performance were obtained. The results showed that the ZnO nanofluid adding SDS/CTAB mixed surfactants has good dispersion stability and thermal physical properties with thermal conductivity up to 0.772 W/(m·K). Moreover, it has the lowest transmittance of 0.10% and the highest extinction coefficient of 7.25 cm-1. Moreover, the addition of SDS/CTAB mixed surfactants makes ZnO nanofluids show better photothermal conversion efficiency, up to 87%. Therefore, ZnO nanofluids with SDS/CTAB added have great potential as working fluids for DASC.

Ginseng‐Bioinspired 3D Photothermal Evaporator for Efficient Seawater Desalination Using Conjugated Microporous Polymer

AbstractPhotothermal conversion technology presents a promising approach for harnessing solar energy to facilitate seawater desalination. However, salts will accumulate on the surface of the photothermal conversion structure during seawater desalination, which hinders solar energy absorption. Meanwhile, the photothermal conversion structure directly immersing in a large water body results in a large heat dissipation loss. Both factors impair solar energy conversion and water steam generation. To address the issues, inspired by a ginseng plant (with a trunk‐to‐branch water supply system), a 3D cotton‐based photothermal evaporator with tunable water supply is facilely designed herein via simple cloak‐weaving of a porphyrin‐based conjugated microporous polymer (PPCMP) as the photothermal conversion material. The as‐designed 3D cloak‐like photothermal evaporator achieves an equilibrium between the water supply flux and evaporation rate via optimizing PPCMP weaving and the water path. As a result, a high evaporation rate of 2.81 kg m−2 h−1 and photothermal conversion efficiency of 155% are obtained under 1 sun illumination. The findings underline the importance of 3D porous organic polymer‐based fabrics as effective media for harnessing solar energy and highlight their potential for seawater desalination.

Photothermal CO2 Catalysis toward the Synthesis of Solar Fuel: From Material and Reactor Engineering to Techno-Economic Analysis.

Carbon dioxide (CO2), a member of greenhouse gases, contributes significantly to maintaining a tolerable environment for all living species. However, with the development of modern society and the utilization of fossil fuels, the concentration of atmospheric CO2 has increased to 400ppm, resulting in a serious greenhouse effect. Thus, converting CO2 into valuable chemicals is highly desired, especially with renewable solar energy, which shows great potential with the manner of photothermal catalysis. In this review, recent advancements in photothermal CO2 conversion are discussed, including the design of catalysts, analysis of mechanisms, engineering of reactors, and the corresponding techno-economic analysis. A guideline for future investigation and the anthropogenic carbon cycle are provided.

A “Transformers”‐like nanochain for precise navigation and efficient cancer treatment

AbstractIntegrated multimodal imaging in theranostics nanomaterials offers extensive prospects for precise and noninvasive cancer treatment. Precisely controlling the structural evolution of plasmonic nanoparticles is crucial in the development of photothermal agents. However, previous successes have been limited to static assemblies and single‐component structures. Here, an activatable plasmonic theranostics system utilizing self‐assembled 1D silver‐coated gold nanochains (1D nanochains) is presented for precise tumor diagnosis and effective treatment. The absorbance of the adaptable core–shell chain structure can shift from visible to near‐infrared (NIR) regions due to the fusion between nearby Au@Ag nanoparticles induced by elevated H2O2 levels in the tumor microenvironment (TME), resulting in the creation of a novel 3D aggregates with strong NIR absorption. With a high photothermal conversion efficiency of 60.2% at 808 nm, nanochains utilizing the TME‐activated characteristics show remarkable qualities for photoacoustic imaging and significantly limit tumor growth in vivo. This study may pave the way for precise tumor diagnosis and treatment through customizable, optically tunable adaptive plasmonic nanostructures.

Second Near‐Infrared Phototheranostics with cGAS‐STING‐Activating Capacity for Photothermal Immunotherapy

AbstractPhotothermal immunotherapy represents an effective approach for eliminating both local and metastatic tumors through priming of the tumor‐specific immune response. Cytosolic delivery of double‐stranded DNA via pH‐responsive vehicles is recently verified to activate the cyclic guanosine monophosphate–adenosine monophosphate (GMP‐AMP) synthase‐stimulator of interferon genes (cGAS‐STING) pathway, which is robust in activating both innate and adaptive antitumor immunity. Herein, multifunctional phototheranostics with excellent photothermal conversion capacity, second near‐infrared (NIR‐II) fluorescence, and cGAS‐STING activating capacity are prepared by encapsulating fish testis DNA and conjugated boron dipyrromethene tetramers with poly(lactic‐co‐glycolic acid) and poly(ethylene glycol)‐b‐poly(lactic‐co‐glycolic acid) via a CaCO3‐assisted double emulsion method. The obtained phototheranostics (coined DB4CaP NPs) after intravenous administration gradually accumulate in tumor regions, as shown by NIR‐II fluorescence imaging. Together with local 915 nm laser exposure, primary tumors in mice treated with DB4CaP NPs could be effectively eradicated, with a complete response of 83.3%. Furthermore, such DB4CaP NPs could synergize with anti‐programmed cell death protein 1 immunotherapy to suppress the growth of distant unirradiated and rechallenged tumors through activating the antitumor immune response. This study highlights a promising strategy for eradicating tumors, particularly invisible and unresectable micronodules, through NIR‐II fluorescence imaging‐guided photothermal immunotherapy.

Photo‐Responsive TiO2‐Gold Nanoparticle‐Polymer Nanohybrid Exhibits Photothermal, Thermo‐Release, and Photocatalytic Effects

The development of multi‐responsive nanohybrid systems that combine photothermia, thermo‐responsive effects and photocatalysis is a challenging topic in the research of multifunctional materials with a large field of applications. Here, we report the first example of a three‐components light‐responsive nanosystem consisting of titania, gold nanoparticles and poly‐N‐isopropylacrylamide (TiO2‐Au‐PNM). The hybrid nanostructure exhibited photothermal conversion effect upon green‐light excitation and capacity to entrap methylene blue and curcumin selected as cargo models. The formation of the nanohybrid―cargo adducts, the photothermal‐controlled cargo release triggered by green‐light irradiation (532 nm) and mediated by lower critical solution temperature (LCST), as well as the photocatalytic effect prompted by UV‐light excitation (300 nm) were demonstrated by spectroscopic techniques. The mechanism involved in the interaction of the polymeric component with the cargos was investigated by molecular modelling calculations.

Facile synthesis of MOF–808/RGO-based 3D macroscopic aerogel for enhanced photoreduction CO2

Three-dimensional (3D) macroscopic aerogels have emerged as a critical component in the realm of photocatalysis. Maximizing the integration of materials can result in enhanced efficiency and selectivity in photocatalytic processes. In this investigation, we fabricated MOF-808/reduced graphene oxide (RGO) 3D macroscopic aerogel composite materials employing the techniques of hydrothermal synthesis and freeze-drying. The results revealed that the macroscopic aerogel material exhibited the highest performance in CO2 reduction to CO, particularly when the concentration of RGO was maintained at 5 mg mL−1. In addition, we synthesized powder materials of MR-5 composite photocatalysts and conducted a comparative analysis in terms of photocatalytic CO2 reduction performance and electron transfer efficiency. The results showthat the macroscopic aerogel material boasts a high specific surface area, an abundant internal pore structure, and increased active sites. These attributes collectively enhance light energy utilization, and electron transfer rates, thereby, improving photothermal and photoelectric conversion efficiencies. Furthermore, we conducted in-situ FT-IR measurements and found that the M/R-5 aerogel exhibited the best CO2 adsorption capacity under a CO2 flow rate of 10 mL min−1. The density functional theory results demonstrate the correlation between the formation pathway of the product and the charge transfer pathway. This study provides useful ideas for realizing photocatalytic CO2 reduction of macroscopic aerogel materials in gas–solid reaction mode.