Broad Light Absorption Research Articles

Three-Dimensional Fully Conjugated Covalent Organic Frameworks for Efficient Photocatalytic Water Splitting.

Covalent organic frameworks (COFs) are promising photocatalysts for water splitting, but their efficiency lags behind that of inorganic counterparts partly due to the limited charge transport and optical absorption properties. To overcome this limitation, we proposed to employ three-dimensional (3D) fully conjugated (FC) COFs with a topological assembly of cyclooctatetraene derivatives for photocatalytic water splitting. On the basis of first-principles calculations, we demonstrated that these 3D FC-COFs are semiconductors with exceptional charge transport and optical absorption properties. The carrier mobilities are comparable to those of inorganic semiconductors and superior to the record mobility observed in two-dimensional COFs. Additionally, the 3D FC-COFs exhibit broad visible light absorption with direct band gaps and high optical absorption coefficients. Among them, two 3D FC-COFs are identified for overall water splitting, while three others can facilitate the hydrogen evolution half-reaction. This study pioneers the design of 3D FC-COF photocatalysts, potentially advancing their applications in photocatalysis and optoelectronics.

Oxygen Vacancies Modified TiO2/O‐Terminated Ti3C2 Composites: Unravelling the Dual Effects between Oxygen Vacancy and High‐Work‐Function Titanium Carbide

AbstractThe rational design of Ti3C2Tx MXene‐derived TiO2‐based photocatalysts with broad light absorption and efficient charge separation has recently attracted considerable attention for antibiotic degradation. However, the complementary effects of each component, especially oxygen vacancies (OVs) and high work function O‐terminated Ti3C2 (O‐Ti3C2), in affecting light absorption and photocatalytic activity remain controversial. In this study, Ti3C2Tx‐derived TiO2/Ti3C2Tx photocatalysts are regulated by alkalization in the controlled KOH solution and calcination in different heating atmospheres to reveal the contribution of OVs, Ti3+, carbon species, and high work function titanium carbide. Carbon species and rich OVs co‐exist in TiO2/O‐Ti3C2 (OV/C‐TT‐1K(N2)) which exhibit superior photocatalytic performance in tetracycline hydrochloride degradation with a kinetic constant of 0.0217 min−1. Combined with experimental and DFT computational results, the broadened visible light response and desirable redox properties are caused by OVs and carbon dopants, as well as decreased Schottky barrier height and enhanced electronic conductivity caused by high work function O‐Ti3C2.

Enhanced photocatalytic Cr(VI) reduction performance by novel PDI/COFs composite

Constructing the heterojunction by using covalent organic frameworks (COFs) is an effective way to promote photocatalytic activity. Herein, we designed and constructed different ratios of PDI/COFs hybrid materials by solvothermal method, denoted as PDI/TAPB-PDA (TAPB = 1,3,5-tris(4-aminophenyl)benzene, PDA = terephthaldehyde) composite. Although the construction of the heterojunction can destroy the long-range order of the TAPB-PDA COF structure to varying degrees, it does not affect the photocatalytic performance of PDI/TAPB-PDA composite. The optimal composite PDI/TAPB-PDA-5 with an initial molar ratio of PDI to TAPB-PDA COF of 32:1 has the highest photocatalytic performance for Cr(VI) reduction. The fitted first-order kinetic reaction rate k of PDI/TAPB-PDA-5 was 12.3 and 3.6 times that of PDI and TAPB-PDA COF, respectively. The superior photocatalytic activity of PDI/TAPB-PDA composite can be attributed to the broadened light absorption range and enhanced separation and transfer of carriers. The construction of composite materials between imine-linked COFs and dye PDI with excellent photocatalytic performance provides the possibility and affordability for realizing the practical application of expensive COFs-based catalysts.

Constructing CoAl-LDO/MoO3−x S-scheme heterojunctions for enhanced photocatalytic CO2 reduction

Converting CO2 into chemicals and fuels by solar energy can alleviate global warming and solve the energy crisis. In this work, CoAl-LDO/MoO3−x (LDO/MO) composites were successfully prepared and achieved efficient CO2 reduction under visible light. The CoAl-layered double oxides (CoAl-LDO) evolved from CoAl-layered double hydroxide (CoAl-LDH) exhibited a more robust structure, broader light absorption, and improved CO2 adsorption ability. The local surface plasmon resonance (LSPR) effect excited by nonstoichiometric MoO3−x broadened the photo-response range of CoAl-LDO/MoO3−x. In addition, constructing step-scheme (S-scheme) heterojunctions could simultaneously optimize the migration mechanism of photogenerated electrons and holes, and retain carriers with strong redox ability. Therefore, the production rates of CO and CH4 on the optimal LDO/MO composite were 7 and 9 times higher than the pristine CoAl-LDH, respectively. This work hybridizes oxidation photocatalysts and LDO-based materials to optimize the charge separation and migration mechanisms, which guides the modification of LDO-based materials.

Vacancy-induced spontaneous H2 evolution by overall water splitting on MoTe2/Ti2CO2: A two-dimensional direct Z scheme heterostructure

Photocatalysts with direct Z-scheme heterostructures hold great potential for hydrogen production by solar-driven overall water splitting. However, building highly efficient direct Z-scheme heterostructures is still a challenge. This work develops a novel MoTe2/Ti2CO2 heterostructure as a potential direct Z-scheme photocatalyst for overall water splitting. First-principles computations utilizing density functional theory (DFT) have been used in this study to carefully study several aspects of the heterostructure, including vdW binding energy, formation of the internal electric field, electronic structure, optical properties, and thermodynamic feasibility of water splitting. According to these calculations, the superior interlayer interaction in MoTe2/Ti2CO2 results in a substantial built-in electric field suitable for carrier separation. These findings indicate that the suggested vdW heterostructure is a direct Z-scheme water-splitting photocatalyst with suitable band alignments and a broad light absorption range. This enhanced interaction resulted in a significant increase of photocurrent compared to both the monolayers. Additionally, it is envisaged that the heterojunction will serve as photocatalyst for the oxygen evolution process (OER) and the hydrogen evolution process (HER). The results demonstrate that MoTe2/Ti2CO2 heterostructure with Te vacancy has a low Gibbs free energy of the HER, favoring spontaneous hydrogen evolution in both acidic and neutral conditions. The suggested heterostructure exhibits a commendable solar-to-hydrogen efficiency of 15.25%, making it a viable option for commercial implementation. This research offers a theoretical foundation for designing novel, two-dimensional overall water-splitting photocatalysts in an effort to produce clean energy.

A Nanophotocatalyst of ZnO/CuS with Photothermal Effect, Superhydrophobicity and Self-Healing Function

Photothermal-assisted photocatalysis is a novel catalytic technology that can not only utilize both light energy and light heat, but also simultaneously incorporate superhydrophobicity and self-healing ability into photocatalysts. It represents a significant advancement in efficient photocatalytic degradation of water pollution. Here, by incorporating the semiconductor photothermal agent CuS on the outer layer of ZnO nanoflowers, the deposited CuS layer exhibits an outstanding photothermal effect under near-infrared light irradiation, which can absorb infrared light and convert it into heat energy, enhancing the performance of the ZnO nanoflowers in situ. Meanwhile, a photothermal conversion surface material with self-healing superhydrophobicity is prepared by using a mixture of beeswax and polydimethylsiloxane. The broad light absorption ability and enhanced charge transfer accelerate the photocatalytic efficiency, in addition, the incorporation of superhydrophobicity enables resistance to corrosive liquid pollution and repairs its superhydrophobicity damage by beeswax migration to provide lasting protection. The degradation rate of MB is as high as 98% within 80 min. Finally, the mechanism of photothermal effect in photocatalysis and the mechanism of self-healing superhydrophobicity are proposed. This work innovatively integrates photothermal effect and self-healing superhydrophobic function into photocatalytic degradation of water pollution technology, which broadens the scope of improving photocatalytic performance and extends the photocatalyst operation life to a certain extent.

Ternary rGO decorated W18O49 @g-C3N4 composite as a full-spectrum-responded Z-scheme photocatalyst for efficient photocatalytic H2O2 production and water disinfection

Integrating g-C3N4 with narrow-band semiconductor to construct a Z-scheme structured heterojunction has been regarded as a common strategy to improve the photocatalytic performance of g-C3N4. However, limited catalytic activity increment is achieved due to the contradiction of expanding the light absorption scope of traditional photo-oxidation semiconductors (PS II) and preserving their valance band oxidative abilities. Herein, to extend the light absorption range of g-C3N4 based Z-scheme photocatalyst to the whole solar spectra while without losing the high oxidative ability of this system, we select the heavy doped W18O49 as PS II and provide a facile in situ hydrothermal method to elaborately fabricate an rGO decorated W18O49 @g-C3N4 (r-CNW) Z-scheme photocatalyst. The prepared r-CNW-2 (with optimal W18O49 to g-C3N4 weight ratio of 1:2) exhibits improved photocatalytic performance with H2O2 generation rates of 71, 58.5 and 6.3 μmol g−1 h−1 obtained under the simulated solar light, visible light (>400 nm) and NIR light (>800 nm) irradiation, respectively, which is 1.3 and 2 times higher than those of the g-C3N4 counterparts (54, 29 μmol g−1 h−1 and even not detected).such outstanding performance of r-CNW-2 could be associated with the broader light absorption, fast charge separation, and rapid redox reactions. Moreover, the r-CNW-2 also displays an excellent E-coli inactivation activity, comparable to most g-C3N4-based photocatalysts. Our work gives a new insight through trading off light absorption and redox ability to fabricate efficient Z-scheme photocatalyst for photocatalytic H2O2 generation and environmental remediation.

Black Phosphorus Nanosheets Grafted with Gold Nanorods and Carbon Nanodots for Synergistic Antitumor Therapy.

Synergetic photothermal/photodynamic/chemotherapy receives significant attention for precise in vivo cancer treatment. Despite plenty of encouraging photosensitizers explored, integrated nanoagents with multiple functions are still highly desired. In this study, novel nanocomposites coupling black phosphorus (BP) nanosheets, gold nanorods (AuNRs), carbon nanodots (CDs), and doxorubicin (Dox) are prepared. The nanoagents exhibit high antitumor activity on account of their broad light absorption, excellent catalytic ability, and significant photothermal and photodynamic effects. CDs not only emit bright fluorescence for accurate diagnosis and guiding of tumor treatment but also catalyze the generation of ROS for photodynamic therapy (PDT). The released Dox induces apoptosis of cells and increases the levels of H2O2 to promote PDT. AuNRs are the main photothermal therapy (PTT) material that converts light into heat. Moreover, BP can be used to enhance both PTT and PDT efficiencies, and the two therapy modes can be cooperatively reinforced. It is also found that the local immune microenvironment of the tumors is activated. The strategy makes good use of the features of each component. Satisfactory antitumor phenomena are well confirmed by in vitro and in vivo results. This study provides new insights into enhanced synergetic therapy, highlighting the great utility of BP-based nanoagents in the field of nanomedicine.

Exploring Different Designs in Thieno[3,4-b]pyrazine-Based Dyes to Enhance Divergent Optical Properties in Dye-Sensitized Solar Cells

Two novel organic sensitizers for Dye-Sensitized Solar Cells (DSSC), called TP1 and TP2, based on the electron-poor thieno[3,4-b]pyrazine (TPz) π-bridge and the electron-rich N,N-bis(4-(hexylthio)phenyl)aniline (TPA) were designed following two different approaches: the classical D-A-π-A design and a symmetric structure with double anchoring functions. Both compounds were prepared exploiting short synthetic pathways based on direct arylation strategies and possibly one-pot desymmetrization. The two novel dyes displayed opposite optical properties: a broad and intense light absorption over the entire visible spectrum for TP1, and a localized absorption that peaked in the center of the visible region for TP2, resulting in a pitch-dark coloration and a green tone, respectively. When assembling the photovoltaic devices, different electrolyte compositions were explored to enhance the optical properties of the dyes. Power conversion efficiencies as high as 5.2% under full sun intensity were recorded for small test devices. The composition of the light transmitted through the TP2-containing transparent DSSC fits well with the human eye sensitivity spectrum, thus fulfilling the transparency requirements for building-integrated photovoltaics (BIPV).

Plasmonic enhanced branched Ag sensitized Cu2O–CuO/TiO2 heterojunction with unprecedented photocatalytic degradation under visible light

A novel plasmonic Ag assisted Cu2O–CuO/TiO2 heterojunction photocatalyst was prepared using a facile sol-gel technique, and its MB degradation efficiency was explored. The physicochemical, morphostructural, and spectroscopic analyses using XRD, UV–vis-DRS, SEM, TEM, Raman, ESR, PL and XPS showed the formation of Ag@Cu2O–CuO/TiO2 hybrid photocatalyst, exhibiting surface plasmon resonance (SPR) and interfacial ternary heterojunctions. The SPR exhibited by the bulbous branched Ag nanostructures resulted in broad visible light absorption that extended into the near-infrared region. This plasmonic-heterojunction hybrid photocatalyst has shown excellent photocatalytic degradation, far surpassing the performance of its pristine counterparts under visible light illumination. The improved photocatalytic degradation of MB is attributable to the synergistic impact of reduced electron-hole pair recombination owing to Cu2O–CuO/TiO2 ternary junction, broad visible light absorption and near-field enhancement through the surface plasmon resonance effect. The current study demonstrates an integrated plasmonic-heterojunction photocatalytic system that offers a promising avenue for enhancing photocatalytic performance in dye-contaminated water treatment.

Rationally designed Ti3C2 MXene/CaIn2S4 Schottky heterojunction for enhanced photocatalytic Cr(VI) reduction: Performance, influence factors and mechanism

As a highly toxic heavy metal, Cr(VI) reduction by developing high-efficiency photocatalysts is of great significance. Herein, we firstly design few-layer Ti3C2 MXene (FTM) by the hand-operated shaking, showing dual advantages of structural stability and more exposed reactive sites. Then, a refluxed process is performed to fabricate FTM/CaIn2S4 (FTC) composites, where 2D CaIn2S4 (CIS) nanoplates are closely connected with 2D FTM to form Schottky junction. The optimal 1-FTC with the FTM/CIS mass ratio of 1 wt.% exhibits the highest activity toward photocatalytic Cr(VI) reduction under visible light. It is well elucidated that the broadened light absorption range and promoted charge carrier separation rate induced by the introduction of FTM are responsible for improving photocatalytic activity of CIS. During Cr(VI) photoreduction, 1-FTC possesses excellent photo-stability and reusability. The effects of catalyst mass, coexisting ions, water sources and pH values on the Cr(VI) photoreduction efficiency are investigated. Photogenerated •O2− and e− are the main radical species accounting for Cr(VI) photoreduction over 1-FTC. The photocatalytic mechanism along with Cr(VI) removal pathway is exploited. This work may provide some insights into constructing FTM-based Schottky junctions for the efficient water purification.

The efficient photothermal performance of organic polymeric material poly3-hexylthiophene for solar driven water evaporation and thermoelectric power generation

Photothermal materials for solar evaporators need to have broad light absorption ability and be able to convert into heat efficiently. At present, organic photothermal materials mainly have the problems of narrow absorption spectrum range and low photothermal conversion efficiency. In recent years, the development of photovoltaic materials has attracted the attention of researchers. However, the application of photovoltaic materials to the field of solar driven water evaporation is still rare. Poly(3-hexylthiophene), P3HT, is a typical p-type conjugated polymer that can achieve high power conversion efficiency. P3HT powder has a solar-thermal conversion efficiency of 11.26%. Its absorption range at 300–900 nm provides effective utilization of sunlight and has the potential as an excellent photothermal conversion material. We loaded P3HT into non-woven fabric to obtain an integrated device for simultaneous water evaporation and thermoelectric power generation, with evaporation rate of 1.04 kg m−2 h−1 and output voltage of 58 mV under 1 kW m−2 simulated solar irradiation. This study enriches the application of traditional photovoltaic materials in the field of solar-heat technique and provides guidance in the construction of solar evaporation devices for water-electricity co-generation.

Oxygen vacancy-rich MoO 3 nanorods as photocatalysts for photo-assisted Li–O 2 batteries

Photo-assisted lithium–oxygen (Li–O₂) batteries have been developed as a new system to reduce a large overpotential in the Li–O₂ batteries. However, constructing an optimized photocatalyst is still a challenge to achieve broad light absorption and a low recombined rate of photoexcited electrons and holes. Herein, oxygen vacancy-rich molybdenum trioxide (MoO_3−<i>x</i>) nanorods are employed as photocatalysts to accelerate kinetics of cathode reactions in the photo-assisted Li–O₂ batteries. Oxygen vacancies on the MoO_3−<i>x</i> nanorods can not only increase light-harvesting capability but also improve electrochemical activity for the cathode reactions. Under illumination, the photoexcited electrons and holes are effectively separated on the MoO_3−<i>x</i> nanorods. During discharging, activated O₂ is reduced to Li₂O₂ by the photoexcited electrons from the MoO_3−<i>x</i> nanorods. The photoexcited holes can promote the decomposition of Li₂O₂ during subsequent charging. Accordingly, the photo-assisted Li–O₂ batteries with the MoO_3−<i>x</i> nanorods deliver an ultralow overpotential of 0.22 V, considerable rate capability, and good reversibility. We think that this work could give a reference for the exploitation and application of the photocatalysts in the photo-assisted Li–O₂ batteries.

Solvent-exfoliated D-A π-polymer @ ZnS heterojunction for efficient photocatalytic hydrogen evolution

Constructing organic/inorganic soft-hard semiconductor heterojunctions has emerged as a promising strategy to design high-performance photocatalysts. Herein, N-methyl pyrrolidone-assisted solvent exfoliation is employed for the first time to the in-situ construction of benzothidiazole (BT) and bithiophene (TT)-based donor-acceptor (D-A) π-polymeric-inorganic heterojunction (i.e., BT-TT@ZnS) for Pt-free photocatalytic hydrogen production (PHP). Despite that the pristine polymer BT-TT has no photocatalytic activity, the BT-TT@ZnS heterostructure, however, shows a photocatalytic hydrogen evolution rate up to 15.8 mmol g−1 h−1 in the absence of Pt co-catalyst, which is also 10.5 times as high as that of pristine ZnS, and outperforms the majority of the previously reported π-polymers photocatalysts. Systematical studies reveal that BT-TT@ZnS heterostructures simultaneously possess the broadened light absorption and the improved charge separation compared to the single components of BT-TT or ZnS. This work develops a facile and generally applicable strategy to construct π-polymer colloids @ inorganic heterostructure for PHP application.

Rapid Synthesis of Oxygen-Deficient MoO3–x-rGO Composites for Synergistic Photothermal Seawater Desalination and Photocatalytic Sterilization

The development of efficient photothermal desalination devices is of great significance in solving the problem of freshwater shortage. The design and preparation of efficient photothermal materials with a broad light absorption range have been extensively studied. However, the performance of photothermal catalysts for synergistic purification of complex seawater is still facing significant challenges. Therefore, we report the rapid preparation of MoO3–x-rGO composites with synergistic photothermal and photocatalytic performance by the solid-phase microwave thermal shock method. The superhot spots created on the surface of microwave-reduced rGO induce the formation of MoO3–x with oxygen vacancies. Due to the localized surface plasmon resonance (LSPR) effect, the near-infrared photothermal and photocatalytic properties of MoO3–x-rGO catalysts are greatly improved. When the optimal composite catalyst (GMW-3) is illuminated by one sunlight, the seawater evaporation rate and photothermal conversion efficiency can reach 1.58 kg m–2 h–1 and 87.2%, respectively. Meanwhile, the GMW-3 composite evaporator shows excellent antibacterial performance under the synergistic effect of photothermal and photocatalysis during the evaporation process. These findings expand a new insight and platform to design efficient catalysts for large-scale seawater desalination and purification.

Stabilization of Perovskite Lattice and Suppression of Sn2+/Sn4+ Oxidation via Formamidine Acetate for High Efficiency Tin Perovskite Solar Cells

AbstractTin halide lead‐free perovskite solar cells (TPSCs) have received tremendous research interest recently due to their nearly ideal bandgap, broad light absorption, non‐toxicity, and environmental friendliness. However, the uncontrollable crystallization process and the facile oxidation of Sn2+ limit the further increase of power conversion efficiency (PCE). To solve these problems, a series of acetates are introduced into the perovskite precursor solution to regulate the crystallization process. It is revealed that formamidine acetate (FAAc) has strong COSn coordination with Sn2+ compared with acetic acid (HAc) and methylammonium acetate (MAAc), which can stabilize the lattice structure, minimize defect states and suppress the oxidation of Sn2+. Meanwhile, benefiting from this coordination ability, it not only leads to large‐size colloidal clusters in precursor but also slows down the crystallization process and improves the crystallinity of tin halide perovskite films. The device with FAAc achieved an increased PCE from initially 9.84% to 12.43%, and it could maintain 94% of its initial value for 2000 h in N2 atmosphere. This work provides a feasible strategy for depositing high‐quality tin perovskite films with low defect density and lattice distortion, which will be crucial for related photovoltaics and other optoelectronic devices.

Organic Conjugated Trimers with Donor–Acceptor–Donor Structures for Photocatalytic Hydrogen Generation Application

AbstractOrganic donor–acceptor–donor (D–A–D) polymers or small molecules are widely investigated in organic solar cells due to their broad light absorption, narrow band gap, excellent charge mobility, and exciton seperation at the interface. However, studies of conjugated small molecules with D–A–D molecule structures as photocatalytically active materials are still rare. In this study, an unprecedented demonstration that photocatalytic activity can in fact be affected by tuning the D and A is given. Especially, the EBE trimer, comprising 3,4‐ethylenedioxythiophene (E) and benzothiadiazole (B) units, exhibits the best photophysical, chemical, and photocatalytic properties compared to other D–A–D combinations of D and A. Detailed kinetic studies show that all trimers in organic solution present relatively long‐lived and highly emissive photogenerated singlet excitons (τ = 4–13 ns; ϕem = 0.5–0.9) as judged by photoluminescence and transient absorption measurements, while in specific cases formation of long‐lived triplet states can be identified. Organic microparticles of the trimers are efficiently formed in aqueous solution by nanoprecipitation, and rapid photoinduced electron release/injection to the solvent is evidenced spectroscopically. The results indicate that organic small molecule structures with D–A–D structures pave a new pathway for photocatalytic solar‐to‐chemical energy conversion of novel small organic molecules.

Multi-Prismatic Hollow Cube CeVO4 with Adjustable Wall Thickness Directed towards Photocatalytic CO2 Reduction to CO.

Ternary orthovanadate compounds have received increasing attention due to their broad light absorption and diverse crystal structure. However, their multi-assembled crystal morphologies are limited mainly due to their initially polyatomic VO4 groups. In this study, multi-prismatic hollow cubic CeVO4 microstructures were fabricated by a one-step solvothermal method without any organic agents. The increase in wall thickness is in accordance with the radial direction of the quadrangular prism. Moreover, the overdose of the V precursor is favorable for the formation of hollow micro-cubic CeVO4, and the wall thickness changes from 200 to 700 nm. Furthermore, these CeVO4 microstructures were applied to photocatalytic CO2 reduction with a maximum CO generation rate of up to 78.12 μmol g-1 h-1 under visible light irradiation, which was several times higher than that of the other samples. This superior photocatalytic activity might be attributed to its good crystallinity and unique exposed interior structure. This study provides guidelines for the multi-assembled structure fabrication of ternary compounds and expands upon the exploration of the spatial structure of multivariate compounds.

S-scheme enhanced photocatalysis on graphitic carbon nitride functionalized with perylene tetracarboxylic diimide

It is a challenge to realize the catalytic conversion of ammonia by photocatalysis under mild conditions, because it is limited by the high photoinduced carrier recombination rate and low photo-absorption efficiency. Herein, we perform the condensation reaction of 3,4,9,10-perylenetetracarboxylic diimide (PTCDA) with graphitic carbon nitride (g-C3N4) nanosheets to obtain a novel organic semiconductor perylene tetracarboxylic diimide (PTCDI) modified g-C3N4 S-scheme heterostructure (named PTCDI@g-C3N4) via thermal-etching and bath process. The obtained PTCDI@g-C3N4 composite shows an obvious improvement in photocatalytic nitrogen reduction rate of 7308.9 μmol L−1 g−1h−1 with methanol under the Xe lamp irradiation, higher than g-C3N4 nanosheets (1215.3 μmol L−1 g−1 h−1). The excellent photocatalytic performance of PTCDI@g-C3N4 heterostructure is ascribed to two advantages: (1) The S-scheme heterojunction between organic semiconductor PTCDI and g-C3N4 nanosheets is profit to suppress carrier recombination and enhance electron utilization efficiency; (2) The utilization rate of g-C3N4 nanosheets to light was promoted due to the existence of PTCDI with broad visible light absorption. This work may help to provide a possibility to realize efficient photocatalytic nitrogen fixation by preparing organic-nonmetallic heterostructure through facile methods.

Synergistic photothermal conversion and photocatalysis in 2D/2D MXene/Bi2S3 hybrids for efficient solar-driven water purification.

Plasmonic hybrids are regarded as promising candidates for water purification due to their structure-dependent photocatalysis and photothermal performance. It remains a challenge to develop materials that possess these two characteristics for efficient water purification. Herein, plasmonic Ti3C2Tx/Bi2S3 two-dimensional (2D)/2D hybrids were prepared for efficient solar-driven water purification via the combination of photothermal conversion and photocatalysis. Benefitting from broad light absorption, large 2D/2D interfaces, and efficient charge transfer, the binary hybrids showed high-efficiency photothermal conversion and photothermal-assisted photocatalytic activity. By depositing these 2D/2D hybrids on a hydrophilic and porous cotton piece, the Ti3C2Tx/Bi2S3 membrane displayed a high water evaporation rate and solar-to-vapor efficiency under one-sun irradiation. The solar-driven evaporation of seawater, heavy metal ion solution, and dye solution jointly indicated that the plasmonic membrane shows great potential for drinkable water generation and industrial wastewater treatment. Most importantly, the synergistic effect of photothermal evaporation and photocatalysis of the Ti3C2Tx/Bi2S3 membrane on water purification was demonstrated. The polluted water can not only be treated by evaporation, but also be degraded via photocatalysis under solar light irradiation. This work provides new insight into designing functional materials for water purification based on the combination of photothermal conversion and photocatalysis.