Outstanding Light Absorption Research Articles

Tandem photoelectrochemical and photoredox catalysis for efficient and selective aryl halides functionalization by solar energy

Tandem photoelectrochemical and photoredox catalysis for efficient and selective aryl halides functionalization by solar energy

Construction of Au modified direct Z-scheme g-C3N4/defective ZnO heterostructure with stable high-performance for tetracycline degradation

The residual antibiotics in water has become an environmental problem and is now deeply concerned. Z-scheme g-C3N4/defective ZnO heterojunction embellished with Au nanoparticles (Au-g-C3N4-ZnO) was synthesized by three sequential procedures, in-situ the preparation of g-C3N4, the guided cultivation of ZnO nanorods on g-C3N4 nanosheets and the deposition of Au nanoparticles. The tailored photocatalysts, imbuing with inherent oxygen vacancies and outstanding light absorption capacity, exhibits unprecedented photocatalysis efficiency for tetracycline (TC) degradation. The formed Au-g-C3N4-ZnO implements broad-spectrum response, intensifying capacity of light harvest and utilization and promoting the separation and transmission efficiency of carriers. Remarkably, the photocatalytic degradation for TC by 2%Au-g-C3N4-ZnO achieves the best degradation efficiency of 74.7% within 30 min under Xe lamp irradiation. It displays excellent stability and acid or alkaline resistance. Besides, the TC degradation pathways are elucidated in line with intermediate degradation products. Finally, a novel Z-scheme heterojunction photocatalytic mechanism is rationally proposed based on the band structure, surface plasmon resonance effect, oxygen vacancies, charge transfer behaviors and active species generation.

Integrated multifunctional device based on Bi2S3/Pd: Localized heat channeling for efficient photothermic vaporization and real-time health monitoring

Solar steam generation as a sustainable and environment-friendly technology offers remarkable potential to address global drinking-water shortage and energy crisis. In this work, a highly efficient solar evaporator is achieved by an innovative solar absorber (Bi2S3/Pd composite) owing excellent photothermal conversion performance. Benefitting from the decreased water evaporation enthalpy in photothermal materials, Bi2S3/Pd composite solar steamer exhibits an outstanding light absorption of 95%, photothermal conversion efficiency of 97%, and an evaporation rate of 1.61 kg m-2 h-1 under one Sun illumination and further purifying water with metal ions removal rate of ~100%. In addition, a solar thermoelectric generator coated with Bi2S3/Pd composite shows better performance of 70.75 μW cm-2. Furthermore, benefiting from the as-prepared Bi2S3/Pd PAAH (polyacrylamide/polyacrylic acid hydrogel) owning excellent shape adaptability, high compressibility, and stable strain-voltage response, it demonstrates sensitive real-time sensing ability to monitor human muscle strength and joint health condition. In this text, the device-level multifunction integrated system is designed with the highlight of converging solar steam conversion, power generation and wearable sensing. It offers new idea and pathway on the intelligent design of integrated-function device in the development of Times of Internet of Thing.

Carbon nanofibers enhanced solar steam generation device based on loofah biomass for water purification

Solar steam generation is regarded as a sustainable method to address the severe water scarcity issue from seawater and/or wastewater. In this paper, carbonized loofah (CL) solar vapor generator has been verified to be an effective photothermal material (PM). The composite of carbon nanofiber (CNF) decorated CL (CL-CNF) with enhanced light trapping capability was realized by in situ chemical vapor deposition. CL and CL-CNF, either as self-floating PMs or solar steam generation device (SSGD) with hydrophobic ethylene vinyl acetate (EVA) foam as a supporter and hydrophilic cotton pad as a water transportation layer, exhibited an outstanding light absorption ability and light-to-heat conversion capability. In virtue of the cooperative function of photothermal conversion and unique 2D water passageway, high-water evaporation rate and photothermal conversion efficiency of 1.72 kg m−2 h−1 and 92.5% for CL-CNF SSGD were achieved under 1 kW m−2 solar irradiation.

Efficient Photocatalytic Hydrogen Evolution and CO2 Reduction: Enhanced Light Absorption, Charge Separation, and Hydrophilicity by Tailoring Terminal and Linker Units in g-C3N4.

Although graphitic carbon nitride (g-C3N4) has been identified as a promising photocatalyst, pristine g-C3N4 has a limited light absorption, insolubility, small specific surface area, and rapid electron-hole pair recombination. In this study, hydroxyl-grafted oxygen-linked tri-s-triazine-based polymer (HGONTP) is achieved through the polycondensation of hydrothermally pretreated dicyandiamide (DCDA). The content of C-O-C linkers and terminal OH groups in HGONTP can be regulated by the cyclization and hydrolysis degrees of DCDA through the replacement of the pendant NH2 groups with OH groups. The HGONTP photocatalyst exhibits an outstanding light absorption from UV to near-IR, possessing a narrow band gap of 2.18 eV, a hydrophilic surface, a large specific surface area of 96.1 m2 g-1, and reduced charge recombination. As a result, HGONTP exhibits a hydrogen evolution rate 27.7-fold higher than that for pristine g-C3N4 (6.54 vs 0.236 mmol g-1 h-1). The apparent quantum yield reaches 12.6% at 420 nm and 4.1% at 500 nm. In addition, the photocatalytic conversion efficiency of CO2 to CO reaches as high as 3.3 μmol g-1 h-1 without cocatalysts and sacrificial agents. The selectivity of CO2 to CO achieves 88.4%. The proposed strategy paves a new avenue to design high-performance polymeric photocatalysts used in water.

3D Graphene‐Based H2‐Production Photocatalyst and Electrocatalyst

AbstractHydrogen (H2) has been deemed as the most promising and valuable alternative to nonrenewable fossil fuels. Photocatalytic and electrocatalytic water splitting are considered to be the most efficient and environmentally friendly approaches for the sustainable H2 evolution reaction (HER). Graphene with a 3D framework has been utilized for the HER due to its unique structure and properties, including its hierarchical network, large specific surface area, diverse pore distribution, outstanding light absorption ability, and excellent electrical conductivity. The large specific surface area and hierarchically porous structure of 3D graphene can not only maximize the exposure of active sites but also promote electron transfer and gas product diffusion. In addition, the free‐standing 3D graphene monolith is easily recycled compared with powder phase support, which can prevent the loss of active catalysts. By making full use of the aforementioned merits, 3D graphene‐based composite materials show great promise as high‐performance catalysts toward photocatalytic and electrocatalytic HER. In this review, recent advances in fabricating 3D graphene‐based composite materials and their applications in both photocatalytic and electrocatalytic HER are summarized and discussed. Furthermore, the current challenges and future vision associated with the design, fabrication, and integration of 3D graphene‐based composite materials toward HER are put forward.

High-absorption solar steam device comprising Au@Bi2MoO6-CDs: Extraordinary desalination and electricity generation

Solar steam generation as a sustainable water purification technology offers remarkable potential to address global drinking-water shortage. In this work, inspired by the marine benthos coral with dendritic structure, an innovative 3D nanocomposite Au@Bi2MoO6-carbon dots (CDs) solar steamer has been prepared: it exhibits outstanding light absorption of 70%, a photothermal conversion efficiency of 97.1% and an evaporation rate of 1.69 kg m−2 h−1 under one sun illumination. This solar steam generator can be used for seawater desalination and has shown an ion removal rate of ~100% in the purification of metal ions, which effectively reduces the ion concentration in seawater. In addition, a solar thermoelectric generator (STEG) has been prepared. Compared with the blank thermoelectric generator, the solar thermoelectric generator coated with Au@Bi2MoO6-CDs shows better performance. The maximum recorded electrical output of the STEG is 97.4 μW cm−2, which is a promising potential solution to the world energy crisis. The unique design of biomimetic nanocomposite materials can help achieve better performance for the solar steamer and electricity generator compared to that of a single-component material. This kind of hybrid material can thus offer pathways to the development of solar thermal technologies applicable in various energy-related applications.

Tunable electronic and optical properties of novel ZnSe/AlP van der Waals heterostructure

Without the constraint originating from lattice matching, two-dimensional (2D) van der Waals (vdW) heterostructure formed by combining 2D materials provides new possibilities to improve the electronic and optical properties of a single material system. Based on the first-principles calculations of density functional theory, the stacking orders, electronic and optical properties of ZnSe/AlP heterostructure were explored by us. The results demonstrate that the stability of the ABI pattern with the interlayer spacing of 2.65 Å is better than other structures and the charge will accumulate between the ZnSe and AlP monolayers. We find that the band gap of the heterostructure is sensitive to changes of the interlayer spacing, external plane strain and electric field. Under in-plane strain, the transition from direct to indirect band gap will occur in the heterostructure, but this phenomenon is not observed to the cases of external electric field. In addition, the band gap will disappear at the 1.0 V/Å for the AAII pattern (−1.0 V/Å for the ABI pattern), wherefore the heterostructure exhibits metallic properties. Compared with the isolated monolayers, the light absorption of the heterostructure at the blue-ultraviolet region is greatly enhanced. The adjustable band gap and outstanding light absorption capacity indicate that the ZnSe/AlP heterostructure is promising as an effective candidate for the optoelectronic devices.

Effect of Cl doping amount on the microstructure, photovoltaic properties and ferroelectric properties of Bi-based lead-free perovskite

Organic–inorganic hybrid perovskites with 3D perovskite structure have gained much attention as light harvesting materials in thin-film photovoltaics. This is because of their outstanding light-absorption characteristics, charge-transport dynamics and their simple processability using lab-scale solution and vapor phase deposition techniques. However, the inherent instability and lead toxicity of lead-based PSCs are the major problems at present. Recent studies have shown that the (CH3NH[Formula: see text]Bi2I9 (MBI) 0D bismuth-based compound can be used as an optical absorption layer in solar cells. In this paper, the (CH3NH[Formula: see text]Bi2I9 was doped with Cl− and a series of (CH3NH[Formula: see text]Bi2I[Formula: see text]Clx films were prepared. The effects of different doping amounts on the microstructure, photovoltaic properties and ferroelectric properties were systematically investigated. Scanning electron microscope (SEM) and Atomic force microscope (AFM) analysis showed that with the increase of doping content, the density of the films increased and the roughness decreased. The photoelectric conversion efficiency of (CH3NH[Formula: see text]Bi2I[Formula: see text]Clx raises with the increase of doping content. For example, the photoelectric conversion efficiency of (CH3NH[Formula: see text]Bi2I3Cl6 is 0.473%. We find that the leakage current descends into the increase in doping content, which may be due to the increase in the film density and the decrease of porosity. These research results have a positive effect on the development of Bi-based lead-free perovskite.

A Facile and General Strategy to Deposit Polypyrrole on Various Substrates for Efficient Solar‐Driven Evaporation

AbstractSolar‐driven evaporation for clean water production is currently considered to be one of the most effective and sustainable strategies to alleviate water shortages because of the sustainability, eco‐friendliness, and inexhaustibility of solar energy. Plenty of effort has been paid to developing easy‐to‐follow methods to fabricate the high‐performance photothermal materials for efficient water evaporation. In this manuscript, a facile and general strategy named chemical vapor deposition polymerization (CVDP) to deposit dark PPy coating layer onto various substrates, which acts as a light absorber to efficiently harvest and convert light to heat for solar‐driven interfacial water evaporation, is reported. The obtained PPy‐coated membranes can achieve an outstanding light absorption and show a high stagnation temperature up to 82.3 °C under 1 sun illumination (1 kW m−2). Furthermore, the water evaporation can be accelerated to 1.41 kg m−2 h−1, corresponding to 81.9% on solar conversion efficiency which is comparable to the results of the state‐of‐the‐art photothermal membranes. Due to the moderate reaction conditions, the PPy coating layer can also be deposited onto different porous substrates to meet different water environments. Such novel and effective CVDP strategy for high‐performance photothermal membrane fabrication contributes to the widespread applications in sustainable clean water production.

Bifunctional, Moth-Eye-Like Nanostructured Black Titania Nanocomposites for Solar-Driven Clean Water Generation.

Solar steam generation and photocatalytic degradation have been regarded as the most promising techniques to address clean water scarcity issues. Although enormous efforts have been devoted to exploring high-efficiency clean water generation, many challenges still remain in terms of single decontamination function, relatively low efficiency, and inability to practical application. Herein, we first report the bioinspired fabrication of black titania (BT) nanocomposites with moth-eye-like nanostructures on carbon cloth for solar-driven clean water generation through solar steam generation and photocatalytic degradation. The moth-eye-like BT nanoarrays can largely prolong the effective propagation path of absorbing light and enhance the scattering of light, thereby exhibiting outstanding light absorption of 96% in the full spectrum. Such hierarchical-nanostructured BT nanocomposites not only impressively achieve solar steam efficiency of 94% under a simulated light of 1 kW m-2 but also show the prominent performance of desalination and steam generation in real life condition. In addition, 96% of rhodamine B is degraded using BT nanocomposites as a photocatalyst in 100 min. The moth-eye-like bioinspired designing concept and bifunctional applications in this study may open up a new strategy for maximizing solar energy utilization and clean water generation.

Black titania/graphene oxide nanocomposite films with excellent photothermal property for solar steam generation

Abstract

Visible-Light Driven Photocatalytic Degradation of Organic Dyes over Ordered Mesoporous CdxZn1–xS Materials

Highly ordered mesoporous CdxZn1–xS materials were obtained via a simple nanoreplication method using a mesoporous silica template with a 3-D bicontinuous cubic Ia3d mesostructure. Combined analyses using X-ray diffraction, N2 sorption, electron microscopy, and diffuse reflectance UV–visible spectroscopy revealed that the ordered mesoporous ternary compound semiconductor materials exhibited well-developed crystalline frameworks, high surface areas of 80–120 m2g–1, uniform mesopore sizes of about 20 nm, ordered arrangement of mesopores, and outstanding visible light absorption properties. Photocatalytic activities were investigated by degradation of methylene blue and rhodamine B under visible light over the mesoporous CdxZn1–xS materials. Due to the high surface area and outstanding light absorption properties, the ordered mesoporous CdxZn1–xS exhibited excellent photocatalytic performances for the degradation of methylene blue and rhodamine B. This study indicates a potential application of the mesoporou...

Synthesis and properties of ultra-long InP nanowires on glass

We report on the synthesis of Au-catalyzed InP nanowires (NWs) on low-cost glass substrates. Ultra-dense and ultra-long (up to ∼250 μm) InP NWs, with an exceptionally high growth rate of ∼25 μm min−1, were grown directly on glass using metal organic vapor phase epitaxy (MOVPE). Structural properties of InP NWs grown on glass were similar to the ones grown typically on Si substrates showing many structural twin faults but the NWs on glass always exhibited a stronger photoluminescence (PL) intensity at room temperature. The PL measurements of NWs grown on glass reveal two additional prominent impurity related emission peaks at low temperature (10 K). In particular, the strongest unusual emission peak with an activation energy of 23.8 ± 2 meV was observed at 928 nm. Different possibilities including the role of native defects (phosphorus and/or indium vacancies) are discussed but most likely the origin of this PL peak is related to the impurity incorporation from the glass substrate. Furthermore, despite the presence of suspected impurities, the NWs on glass show outstanding light absorption in a wide spectral range (60%–95% for λ = 300–1600 nm). The optical properties and the NW growth mechanism on glass is discussed qualitatively. We attribute the exceptionally high growth rate mostly to the atmospheric pressure growth conditions of our MOVPE reactor and stronger PL intensity on glass due to the impurity doping. Overall, the III–V NWs grown on glass are similar to the ones grown on semiconductor substrates but offer additional advantages such as low-cost and light transparency.

17.6%-Efficient Radial Junction Solar Cells Using Silicon Nano/Micro Hybrid Structure

We develop a unique nano- and microwire hybrid structure by selectively modifying only the tops of microwires using metal-assisted chemical etching. The proposed nano/micro hybrid structure not only minimizes surface recombination but also absorbs 97% of incident light under AM 1.5G illumination, demonstrating outstanding light absorption compared to that of planar (59%) and microwire arrays (85%). The proposed hybrid solar cells with areas of 1 cm2 exhibit power conversion efficiencies (Eff) of up to 17.6% under AM 1.5G illumination. In particular, the solar cells show a high short-circuit current density (Jsc) of 39.5 mA·cm-2 because of the high light-absorbing characteristics of the nanostructures. This corresponds to an approximately 61.5% and 16.5% increase in efficiency compared to that of a planar silicon solar cell (Eff = 10.9%) and a microwire solar cell (Eff = 15.1%), respectively. Therefore, we expect the proposed hybrid structure to become a foundational technology for the development of highly efficient radial junction solar cells.

17.6%-Efficient radial junction solar cells using silicon nano/micro hybrid structures.

We developed a unique nano- and microwire hybrid structure by selectively modifying only the tops of microwires using metal-assisted chemical etching. The proposed nano/micro hybrid structure not only minimizes surface recombination but also absorbs 97% of incident light under AM 1.5G illumination, demonstrating outstanding light absorption compared to that of planar (59%) and microwire arrays (85%). The proposed hybrid solar cells with an area of 1 cm(2) exhibit power conversion efficiencies (Eff) of up to 17.6% under AM 1.5G illumination. In particular, the solar cells show a high short-circuit current density (Jsc) of 39.5 mA cm(-2) because of the high light-absorbing characteristics of the nanostructures. This corresponds to an approximately 61.5% and 16.5% increase in efficiency compared to that of a planar silicon solar cell (Eff = 10.9%) and a microwire solar cell (Eff = 15.1%), respectively. Therefore, we expect the proposed hybrid structure to become a foundational technology for the development of highly efficient radial junction solar cells.

Novel Sieve-Like SnO2/TiO2 Nanotubes with Integrated Photoelectrocatalysis: Fabrication and Application for Efficient Toxicity Elimination of Nitrophenol Wastewater

A novel electrode with excellent photocatalytic (PC) and electrocatalytic (EC) performances was prepared by assembling sieve-like macroporous Sb-doped SnO2 (Mp-SnO2) film on vertically aligned TiO2 nanotubes (TiO2NTs) through a block copolymer soft-template method. The pore size of Mp-SnO2 ranges from 150 to 400 nm. The construction of the macropore can increase the specific surface area and provide more active sites. The band gap of the Mp-SnO2/TiO2NTs is 2.93 eV, and it presents outstanding light absorption and photoelectrochemical properties. Under the light irradiation of 365 nm, a high photoelectric conversion efficiency of 35.2% can be obtained on Mp-SnO2/TiO2NTs, 3.1 times higher than that on TiO2NTs. Compared with traditional SnO2/Ti electrodes, the Mp-SnO2/TiO2NTs displays smaller electrochemical impedance, a larger electrochemical surface absorption volume, and lower reaction activation energy. The integrated photoelectrocatalytic (PEC) oxidation of p-nitrophenol wastewater on Mp-SnO2/TiO2NTs is...