Photothermal Conversion Ability Research Articles

Preparation and performance enhancement of MXene/Na2HPO4·12H2O@SiO2 phase change microcapsule

Currently, the leakage problem of phase change materials can be solved by the microencapsulation technology. Inorganic hydrated salt materials have the advantages of high latent heat density, high thermal conductivity and low cost. How to construct inorganic hydrated salt microcapsules with excellent heat storage capacity and photothermal conversion performance maintains a challenge. In this work, the MXene/Na2HPO4·12H2O@SiO2 (MXene/MPCMs) composite phase change microcapsules were designed and prepared. The Na2HPO4·12H2O was directly used as phase change material and TEOS was used as raw material to generate SiO2 wall material. The MXene played a key and important role in simultaneously enhancing their photothermal conversion efficiency while maintaining available latent heat. The prepared composite microcapsules (MPCM-1) showed more obvious heat storage and release characteristics, and the latent heat reached 169.62 J/g. Besides, when the hydrated salt was encapsulated in silica shell, the supercooling degree of hydrated salt was reduced from 14.2 °C to 10.1 °C. With the increase of MXene content, the maximum surface temperature of microcapsules significantly increased. Based on the results of surface temperature distribution, the photothermal conversion ability and heat transfer rate of microcapsules were effectively improved, which was mainly attributed to the remarkable light absorption conversion ability of MXene. When the MXene was added, the MXene/MPCMs still showed excellent heat storage properties (~ 156.64 J/g). At the same time, the MXene/MPCMs showed good chemical compatibility, crystallization characteristics and thermal stability. Considering available performance enhancement, the prepared microcapsules show good application prospect in solar energy utilization.

Coordination assembly and NIR photothermal conversion of Metal-organic framework based on 5-(2-cyanophenoxy) isophthalic acid

The development of new photothermal conversion materials in the field of metal-organic frameworks (MOFs) shows broad prospects, but their design synthesis and proper mechanism analysis are still full of huge challenge. Here, four novel MOFs were constructed with 5-(2-cyanophenoxy) isophthalic acid, {Ni(2-CB-IPA)(bpp)(H2O)}n (1), {Ni2(2-CB-IPA)2(bpa)2(H2O)2}n (2), {Co(2-CB-IPA)(bpp)}n (3), {Mn2(2-CB-IPA)2 (bpp)(H2O)2}n (4). (Where 2-CB-IPA = 5-(2-cyanophenoxy) isophthalic acid, bpa = 1,2-bis(4-pyridine)-ethane; and bpp = 1,3-bis(4-pyridyl)propane). The absorption peak at 730 nm in the near-infrared region indicates that different charge transfer interactions affect the photothermal conversion ability. Under laser irradiation (730 nm, 0.45 W cm−2), such compounds exhibit different and distinct warming processes (1 from 20.8 to 91.8 °C; 2 from 20.1 °C to 86.2 °C; 3 from 20.6 to 77.1 °C) except for compound 4. The excellent crystallinity of these materials after irradiation demonstrates excellent thermal stability and cycling durability. Subsequently, further research on the structure-activity relationship revealed that strong π - π interactions are also the reason for the excellent performance of NIR photothermal conversion of 1 under the premise of high NIR absorption. This work provides a visual platform for the photothermal phenomena of crystalline materials.

Solar-Driven Drum-Type Atmospheric Water Harvester Based on Bio-Based Gels with Fast Adsorption/Desorption Kinetics.

Sorption-based atmospheric water harvesting is an attractive technology for exploiting unconventional water sources. A critical challenge is how to facilitate fast and continuous collection of potable water from air. Here, a bio-based gel (CAL gel), resulting from the integration of a whole biomass-derived polymer network with lithium chloride is reported. A fast adsorption/desorption kinetics, with a water capture rate of 1.74kg kg-1 h-1 at 30% relative humidity and a desorption rate of 1.98kg kg-1 h-1, was simultaneously realized in one piece of CAL gel, because of its strong hygroscopicity, hydrophilic network, abundant water transport channels, photothermal conversion ability, and ∼200-μm-thick self-supporting bulky structure caused by multicomponent synergy. A solar-driven, drum-type, tunable, and portable harvester is designed that can harvest atmospheric water within a brief time. Under outdoor conditions, the harvester with CAL gels operates 36 switches (180°) per day realizes a water yield of 8.96kg kggel -1 (18.87g kgdevice -1). This portable harvester highlights the potential for fast and scalable atmospheric water harvesting in extreme environments. This article is protected by copyright. All rights reserved.

Colorimetric and Photothermal Dual-Modal Switching Lateral Flow Immunoassay Based on a Forced Dispersion Prussian Blue Nanocomposite for the Sensitive Detection of Prostate-Specific Antigen.

Prostate-specific antigen (PSA) is a key marker for a prostate cancer diagnosis. The low sensitivity of traditional lateral flow immunoassay (LFIA) methods makes them unsuitable for point-of-care testing. Herein, we designed a nanozyme by in situ growth of Prussian blue (PB) within the pores of dendritic mesoporous silica (DMSN). The PB was forcibly dispersed into the pores of DMSN, leading to an increase in exposed active sites. Consequently, the atom utilization is enhanced, resulting in superior peroxidase (POD)-like activity compared to that of cubic PB. Antibody-modified DMSN@PB nanozymes serve as immunological probes in an enzymatic-enhanced colorimetric and photothermal dual-signal LFIA for PSA detection. After systematic optimization, the LFIA based on DMSN@PB successfully achieves a 4-fold amplification of the colorimetric signal within 7 min through catalytic oxidation of the chromogenic substrate by POD-like activity. Moreover, DMSN@PB exhibits an excellent photothermal conversion ability under 808 nm laser irradiation. Accordingly, photothermal signals are introduced to improve the anti-interference ability and sensitivity of LFIA, exhibiting a wide linear range (1-40 ng mL-1) and a low PSA detection limit (0.202 ng mL-1), which satisfies the early detection level of prostate cancer. This research provides a more accurate and reliable visualization analysis methodology for the early diagnosis of prostate cancer.

Liquid crystal elastomer-based all-printed actuator and sensing array systems

Liquid crystal elastomers (LCEs) are valuable in soft actuators, sensors and other emerging fields. However, it is still a huge challenge to build high-performance LCE-based functional devices in a simple and fast way to achieve the orderly and patterned integration of multiple functional layers and LCE. Herein, screen-printing technology is used to realize the multi-layer pattern deposition of silver fractal dendrites conductive ink (with excellent Joule heating effect and strain-sensing function) and carbon black conductive ink (with photothermal conversion ability) on the surface of LCE. A series of LCE-based electronic devices are prepared through customized printing patterns. The as-obtained actuator possesses excellent electric actuating performance (bending angle of 102° at 200 mA) and self-sensing function (maximum relative resistance changes of −55.0 %), and also exhibits NIR light-driven self-sensing bending actuation behavior (bending angle of 81° at 1.43 W/cm2), which can be used to control the robotic arm. The as-printed NIR light sensing array system can accurately sense the intensity, spot size and position of NIR light, showing good application potential in the field of unmanned aerial vehicle flight safety. This work provides a new strategy for the efficient preparation of LCEs-based flexible electronics.

Magnetic graphene oxide functionalized alginate-g-poly(2-hydroxypropylmethacrylamide) nanoplatform for near-infrared light/pH/magnetic field-sensitive drug release and chemo/phototherapy

Multifunctional nanoplatforms developed from natural polymers and graphene oxide (GO) with enhanced biological/physicochemical features have recently attracted attention in the biomedical field. Herein, a new multifunctional near-infrared (NIR) light-, pH- and magnetic field-sensitive hybrid nanoplatform (mGO@AL-g-PHPM@ICG/EP) is developed by combining iron oxide decorated graphene oxide nanosheets (mGO) and poly(2-hydroxypropylmethacrylamide) grafted alginate (AL-g-PHPM) copolymer loaded with indocyanine green (ICG) and etoposide (EP) for chemo/phototherapy. The functional groups, specific crystal structure, size, morphology, and thermal stability of the nanoplatform were fully characterized by XRD, UV, FTIR, AFM/TEM/FE-SEM, VSM, DSC/TG, and BET analyses. In this platform, the mGO and ICG, as phototherapeutic agents, demonstrate excellent thermal effects and singlet oxygen production under NIR-light (808 nm) irradiation. The XRD and DSC analysis confirmed the amorphous state of the ICG/EP in the nanoparticles. In vitro photothermal tests proved that the mGO@AL-g-PHPM@ICG/EP nanoparticles had outstanding light stability and photothermal conversion ability. The in vitro release profiles presented NIR light-, pH- and magnetic field-controlled EP/ICG release behaviors. In vitro experiments demonstrated the excellent antitumor activity of the mGO@AL-g-PHPM@ICG/EP against H1299 tumor cells under NIR laser. Benefiting from its low-cost, facile preparation, and good dual-modal therapy, the mGO@AL-g-PHPM@ICG/EP nanoplatform holds great promise in multi-stimuli-sensitive drug delivery and chemo/phototherapy.

Dual-drive energy conversion plasmonic Ag@MXene thermal management textiles inspired by bearing structure

Multifunctional wearable textiles can simulate human perception and convert it into visual data, which has advanced application prospects. As an important branch, thermal management wearable textiles have been widely concerned in the aspects of thermal insulation, flame retardant, photothermal anti-icing, electrothermal deicing and even water evaporation. Here, inspired by the bearing structure, we simply soaked the PET textile in Ag@MXene hybrid solution several times to form a Ag@MXene conductive network with Ag NPs as the connection point on the textile fiber, and finally carry out hydrophobic modification. Based on plasma effect, the synergistic action of Ag NPs and MXene enhances the photothermal response of the material. In addition, the addition of Ag NPs effectively reduces the stacking between MXene layers and forms a Ag@MXene conductive network with Ag NPs as the connection point on the textile fibers. The stable temperature range of PDMS/Ag@MXene PET textile is 70–80 °C under one solar illumination intensity, and the stable temperature of PDMS/Ag@MXene PET textile can reach 117 °C at a constant voltage of 3 V. Based on the excellent thermal effect, this textile achieves photothermal anti-icing, electric thermal de-icing, keeping warm and removing sweat. The textile has a water evaporation efficiency of about 0.58 g h−1, which can achieve excellent anti-sweat function. Finally, the textile also achieved rapid flame retardant within 7 s. PDMS/Ag@MXene PET textile processes excellent photothermal and electrothermal conversion ability, acid/water stability and flame retardant ability, and has promising application prospects in thermal management textiles such as deicing and anti-icing, fire prevention, warmth and water evaporation.

Photothermal therapy of xenografted tumor by carbon nanoparticles-Fe(II) complex

Due to the unique structure, carbon nanomaterials could convert near-infrared (NIR) light into heat efficiently in tumor ablation using photothermal therapy (PTT). However, none of them has been applied in clinical treatment, because they have not been approved for clinical evaluations and the precise temperature control facility is scarce. In this study, we designed a temperature-responsive controller for PTT and used carbon nanoparticles-Fe(II) complex (CNSI-Fe) as photothermal conversion agent (PTA) for PTT of tumor in vitro and in vivo. CNSI-Fe was an innovative drug under the evaluations in clinical trials. CNSI-Fe showed excellent photothermal conversion ability in water to increase the water temperature by 40 °C within 5min under irradiation of 808nm laser at 0.5W/cm2. The temperature was precisely controlled at 52 °C for both in vitro and in vivo tumor inhibition. CNSI-Fe with NIR irradiation showed higher tumor cell inhibition than CNSI. In tumor bearing mice, CNSI-Fe with NIR irradiation achieved an inhibition rate of 84.7% and 71.4% of them were completely cured. Mechanistically, CNSI-Fe under NIR irradiation induced the radical generation, oxidative damage and ferroptosis to kill tumor. In addition, CNSI-Fe showed good biosafety during PTT according to hematological, serum biological and histopathological examinations. These results indicated that the combination of chemotherapy and PTT provided higher antitumor efficiency using CNSI-Fe as PTA.

Photothermal-responsive lignin-based polyurethane with mechanically robust, fast self-healing, solid-state plasticity and shape-memory performance

In light of the depletion of petrochemical resources and increase in environmental pollution, there has been a significant focus on utilizing natural biomass, specifically lignin, to develop sustainable and functional materials. This research presents the development of a lignin-based polyurethane (DLPU) with photothermal-responsiveness by incorporating lignin and oxime-carbamate bonds into the molecular chain of polyurethane. The abundant hydrogen bonds between lignin and the polyurethane matrix, along with its cross-linked structure, contribute to DLPU's excellent mechanical strength (30.2 MPa) and toughness (118.7 MJ·m−3). Moreover, the excellent photothermal conversion ability of DLPU (54.4 %) activates dynamic reversible behavior of oxime-carbamate bonds and hydrogen bonds, thereby endowing DLPU with exceptional self-healing performance. After 15 min of near-infrared irradiation, DLPU achieves self-healing efficiencies of 96.0 % for tensile strength and 96.3 % for elongation at break. Additionally, DLPU exhibits photocontrolled solid-state plasticity as well as an excellent phototriggered shape-memory effect (70 s), with shape fixity and recovery ratios reaching 98.8 % and 95.3 %, respectively. By exploiting the spatial controllability and photothermal-responsiveness of DLPU, we demonstrate multi-dimensional responsive materials with self-healing and shape-shifting properties. This work not only promotes the development of multi-functional polyurethanes but also provides a pathway for the high-value utilization of lignin.

Shape Memory Polyurethane Composite With Fast Response to Near-Infrared Light Based on Tannic Acid-Iron and Dynamic Phenol-Carbamate Network.

Intelligent materials derived from green and renewable bio-based materials garner widespread attention recently. Herein, shape memory polyurethane composite (PUTA/Fe) with fast response to near-infrared (NIR) light is successfully prepared by introducing Fe3+ into the tannic acid-based polyurethane (PUTA) matrix through coordination between Fe3+ and tannic acid. The results show that the excellent NIR light response ability is due to the even distribution of Fe3+ filler with good photo-thermal conversion ability. With the increase of Fe3+ content, the NIR light response shape recovery rate of PUTA/Fe composite films is significantly improved, and the shape recovery time is reduced from over 60 s to 40s. In addition, the mechanical properties of PUTA/Fe composite film are also improved. Importantly, owing to the dynamic phenol-carbamate network within the polymer matrix, the PUTA/Fe composite film can reshape its permanent shape through topological rearrangement and show its good NIR light response shape memory performance. Therefore, PUTA/Fe composites with high content of bio-based material (TA content of 15.1-19.4%) demonstrate the shape memory characteristics of fast response to NIR light; so, it will have great potential in the application of new intelligent materials including efficient and environmentally friendly smart photothermal responder.

Composite porous 3D foam for solar-driven atmospheric water harvesting in low humidity natural environment

Solar-driven atmospheric water harvesting (SAWH) has been recognized as a promising strategy to alleviate the freshwater crisis. Herein, we developed an efficient porous polymeric foam, LiCl@CCP-PPy, which has low preparation cost, strong adaptability and portability, and is very suitable for use as a wicking material in SAWH systems. LiCl@CCP-PPy contains abundant –NH2 and –OH groups. These hydrophilic groups and excellent pore structure (porosity is 80.22 %) make it have a good moisture absorption effect even in low humidity environment. The moisture absorption capacity can reach 2.86 g/g at 35 % RH and 25 °C, and 4.48 g/g at 25 °C and 90 % RH. The saturated water absorption effect was 27.48 g/g. LiCl@CCP-PPy can be scaled up for production. In addition, LiCl@CCP-PPy has a high light absorption rate of more than 90 %, and the strong photothermal conversion ability of Polypyrene (PPy) enables the material to warm up rapidly under natural light, thereby accelerating the desorption process (96 % desorption rate at 1 kW/m2 for 3 h). Based on the above properties, LiCl@CCP-PPy was applied to the Tengger desert in northwest China. The final water production efficiency was 0.64 L/m2/d, and the collected water quality met the international drinking water standard.

Electrospun PAN/BaTiO3/MXene nanofibrous membrane with significantly improved piezoelectric property for self-powered wearable sensor

The power supply system is an important part of modern electronic equipment. Traditional batteries have disadvantages such as large volume and poor flexibility. Nanogenerators possess characteristics such as miniaturization, sustainable power supply, and independence from external energy sources. In this work, a piezo-triboelectric hybridized nanogenerator is developed. Barium titanate (BaTiO3) and MXene (Ti3C2) are incorporated into the electrospinning process of polyacrylonitrile (PAN), resulting in an electrospun PAN/BaTiO3/MXene nanofibrous membrane with significantly enhanced piezoelectric properties in comparison with the pure PAN fibrous membrane. Meanwhile, the electronegative properties of the PAN/BaTiO3/MXene nanofibrous membrane are augmented as the negative layer during contact and separation friction. The piezoelectric output voltage of the PAN/BaTiO3/MXene nanofibrous membrane reaches up to 6.4 V. When a nickel-copper conductive fabric is used as the positive layer, the piezo-triboelectric hybridized nanogenerator produces an output voltage of 11.3 V, an output current of 300nA, and a maximum output power density of 3.4 mW·m−2 over a contact-separation area of only 2 × 2 cm2. In addition, given that MXene itself exhibits excellent photothermal conversion ability, the PAN/BaTiO3/MXene nanofibrous membrane can be quickly heated up to about 54℃ under near-infrared irradiation at a power of 0.8 W·cm−2, highlighting its potential in photothermal-therapy applications.

NIR-Mediated Deformation from a CNT-Based Bilayer Hydrogel.

Shape-shifting polymers are widely used in various fields such as intelligent switches, soft robots and sensors, which require both multiple stimulus-response functions and qualified mechanical strength. In this study, a novel near-infrared-light (NIR)-responsible shape-shifting hydrogel system was designed and fabricated through embedding vinylsilane-modified carbon nanotubes (CNTs) into particle double-network (P-DN) hydrogels by micellar copolymerisation. The dispersed brittle Poly(sodium 2-acrylamido-2-methylpropane-1-sulfonate) (PNaAMPS) network of the microgels can serve as sacrificial bonds to toughen the hydrogels, and the CNTs endow it with NIR photothermal conversion ability. The results show that the CNTs embedded in the P-DN hydrogels present excellent mechanical strength, i.e., a fracture strength of 312 kPa and a fracture strain of 357%. Moreover, an asymmetric bilayer hydrogel, where the active layer contains CNTs, can achieve 0°-110° bending deformation within 10 min under NIR irradiation and can realise complex deformation movement. This study provides a theoretical and experimental basis for the design and manufacture of photoresponsive soft actuators.

Versatile Ce(III)‐Terephthalic Acid@Au metal organic frameworks for ROS elimination and photothermal sterilization

Nanozymes have been widely used for treating reactive oxygen species (ROS) caused diseases. However, the ROS‐dependent antibacterial property is inevitably damaged during the process of scavenging ROS, which is unfavorable for the treatment of diseases related to both ROS accumulation and bacterial infections. To address the issues, biomedical materials with both ROS‐elimination ability and ROS‐independent antibacterial capacity are fabricated via in situ depositing spherical Au nanoparticles (Au NPs) on rough surface of metal organic frameworks composed of Ce(III) and terephthalic acid (Ce‐BDC@Au MOFs). The synthesized Ce‐BDC@Au MOFs showed multi‐enzymatic activities owing to the reversible conversion between Ce3+ and Ce4+, and can significantly scavenge ROS in cancer cells. The deposition of spherical Au NPs on surface of Ce‐BDC MOFs causes Au NPs to come close proximity for forming plasmon resonance coupling, inducing the resonance wavelength of Au NPs red shifted to NIR region. Based on this, Ce‐BDC@Au MOFs show good photothermal conversion efficiency under NIR laser (808 nm) irradiation. Benefitting from rough surface and photothermal conversion ability, Ce‐BDC@Au MOFs have high antibacterial efficiency against staphylococcus aureus through both mechanically damaging and photothermal destruction. This strategy is biosafety and effectiveness for treating diseases related to both ROS accumulation and bacterial infections.

Preparation and thermal conductivity enhancement of binary non-eutectic phase change materials based on alum-urea for solar heat storage system

Heat accumulators using latent heat storage are commonly used in solar energy storage systems. Potassium aluminum sulfate dodecahydrate (Alum) is an inexpensive phase change material, but the high phase change temperature limits its application in heat accumulator. To address this limitation is controlling the melting temperature of Alum. In this study, Alum-urea mixtures were first developed by adding 10 wt% urea. Modified phase change materials (MPCM) without phase separation and supercooling were developed by adding NiSO4·6H2O and xanthan gum to the Alum-urea mixture. Composite phase change materials (CPCM) with high thermal conductivity were developed by loading MPCM in expanded graphite. The melting temperature of the Alum-urea mixture was 72.52 °C with 10 wt% urea content, which was 21.4% lower compared to the Alum. The MPCM still has a high phase change enthalpy (157.7 J·g−1) and ignorable subcooling degree (0.8 °C). The thermal conductivity of CPCM is increased by 16 times, and it has good photothermal conversion ability. The CPCM holds significant promise for applications in latent heat energy storage.

Novel silicene-mesoporous silica nanoparticles conjugated gemcitabine induced cellular apoptosis via upregulating NF-κB p65 nuclear translocation suppresses pancreatic cancer growth in vitro and in vivo

Pancreatic cancer’s high fatality rates stem from its resistance to systemic drug delivery and aggressive metastasis, limiting the efficacy of conventional treatments. In this study, two-dimensional ultrathin silicene nanosheets were initially synthesized and near-infrared-responsive two-dimensional silicene-mesoporous silica nanoparticles (SMSNs) were successfully constructed to load the clinically-approved conventional pancreatic cancer chemotherapeutic drug gemcitabine. Experiments on nanoparticle characterization show that they have excellent photothermal conversion ability and stability. Then silicene-mesoporous silica nanoparticles loaded with gemcitabine nanoparticles (SMSN@G NPs) were employed in localized photothermal therapy to control pancreatic tumor growth and achieve therapeutic effects. Our research confirmed the functionality of SMSN@G NPs through immunoblotting and apoptotic assays, demonstrating its capacity to enhance the nuclear translocation of the NF-κB p65, further affect the protein levels of apoptosis-related genes, induce the apoptosis of tumor cells, and ultimately inhibit the growth of the tumor. Additionally, the study assessed the inhibitory role of SMSN@G NPs on pancreatic neoplasm growth in vivo, revealing its excellent biocompatibility. SMSN@G NPs have a nice application prospect for anti-pancreatic tumors.

Double-shell microstructures based on thermochromic materials and biomass flame retardants towards solving the fire and icing hazards

Due to the extreme dynamic weather, important industrial facilities and infrastructure providing vital support for people’s lives usually face the hazards of fire and icing, especially in the weather of thunderstorm and ice. Therefore, to further establish a safe community, we develop a dual-functional polyurea (PUA) coating used as protective materials by introducing flame retardancy and solar de-icing performance. Based on the microencapsulation and electrostatic self-assembly technologies, flame-retardant and thermochromic microcapsules (TCM) are firstly prepared and then added into PUA resin, by using melamine resin and bio-based phytic acid/chitosan (PA/CS) hybrids as double-shell materials. The high phosphorus content of PA and the carbon-forming effect of CS together play a synergistic flame retardant effect, not only improving the thermal stability of microcapsules but also enhancing the flame retardant property of PUA coating. In the cone calorimetry test, the ignition time of TCM@PA/CS@PUA-3 is longer, and the pHRR is reduced by 19.93 %, which shows the improvement of flame retardant performance. Due to the thermochromic mechanism, TCM@PA/CS@PUA composite coatings are able to adjust the photo-thermal conversion ability according to different environment temperature, achieving less temperature in hot environment and higher temperature in cold environment. The excellent photo-thermal conversion ability also promotes the ice melting and slide in 525 s. This polyurea composite coating with both flame retardant and de-icing properties shows great potential for maintaining the normal operation and safety of outdoor industrials and infrastructure in extremely dynamic weather conditions.

Synergistic enhancement of photothermal energy storage capacity of polyethylene glycol by polydopamine and nano-copper particles

Phase change materials (PCMs) are a crucial focus of research in the field of photothermal energy storage. However, due to their inherently low photothermal conversion efficiency, traditional PCMs absorb solar energy scarcely. The photothermal conversion ability of PCMs are usually enhanced by incorporating photothermal conversion nanoparticles. Polydopamine (PDA) is widely used in various fields due to its excellent photothermal conversion and adhesion performance. We dispersed PDA into PEG containing CuNPs to test the effect of PDA on thermal properties of cPCMs. Our team has conducted experiments to test the thermal characteristics and photothermal conversion ability of cPCMs. Results demonstrated that the addition of PDA mitigated the enthalpy loss caused by integrating CuNPs. The enthalpy of melting of cPCMs with addition of polydopamine is greater than that without polydopamine for the composites with different mass fractions. The addition of PDA in cPCMs enhanced their photothermal conversion capacity, resulting in higher temperatures being achieved within the same exposure time compared to samples without PDA. Therefore, the cPCMs with dispersed polydopamine can store higher energy. Meanwhile, PDA also improved the overall thermal conductivity of the material. Our work provided a new method to utilize the photothermal properties of polydopamine. Meanwhile, it can reduce the cost of photothermal energy storage PCMs and further improve the potential of PCM energy storage.

In-situ lignin regeneration facilitated corn straw-based photothermal evaporator with high cost-effectiveness

Solar evaporators are one of the most efficient and sustainable water purification strategies, but it requires the use of expensive photothermal materials. Herein, the surface of waste corn straw was modified with condensed lignin by means of in-situ lignin regeneration. The resulting material was composited with hydrophilic chitosan and then applied as a sustainable and cost-effective photothermal material to construct a solar evaporator. The non-radiative transport was conferred by π-π stacking between conjugated aromatic rings of lignin, allowing the composites to demonstrate promising photothermal conversion ability. The composites presented a max evaporation rate of ∼1.44 kg m−2 h−1 under 1 sun, plus they consistently produced clean water in aqueous organic dye solutions (100 ppm RhB dye and 100 ppm MB dye) and seawater. Due to the ultra-low cost of raw materials and uncomplicated manufacturing procedure, these composites displayed a cost-effectiveness of ∼475 g h−1 $−1. Thus, this work provides a green and sustainable method for converting agricultural waste into functional photothermal evaporators, which is meaningful for both materials and environmental science.

0D/2D Bi2MoO6 quantum dots /rGO heterojunction boosting full solar spectrum-driven photothermal catalytic CO2 reduction to solar fuels

The photothermal-catalyzed CO2 reduction is severely limited by the low carrier transport capacity. In this paper, the in-situ construction of 0D/2D Bi2MoO6 (BMO)/reduced Graphene Oxide (rGO) heterojunction was synthesized. The excellent photothermal conversion ability of rGO promotes the high dispersion of BMO quantum dots (QDs). The size of synthesized BMO QDs is about 4.26 nm and the temperature of the catalysts can quickly rise to 68.0 °C. XPS results show that the C–O–Bi interfacial electronic bridge between surface oxygen-containing groups and BMO QDs was successfully induced by modulating the degree of GO reduction. Electrons generated by BMO QDs migrate to the rGO surface rapidly, inducing rGO as a new electron-rich surface for rapid activation of CO2. The 1:5 BMO/rGO (NaBH4) CO yield reaches 186.87 μmol/g, which is 4.64 times as much as BMO QDs.