Light Absorption Research Articles

Effect of Nickel Impurities in Pyrite on Catalytic Degradation of Thiosulfate

The effects of nickel content in nickel-bearing pyrite on photocatalytic properties, light absorption properties, and oxidative decomposition of thiosulfate were studied. The leaching experiments show that the consumption of thiosulfate in the Cu2+-ethylenediamine (en)-S2O32− system increases with an increase in nickel content in nickel-bearing pyrite. The consumption of Cu(en)22+ initially increases and then decreases with an increase in leaching time. There is a clear correlation between the change trend in its consumption and the doping amount of nickel in pyrite. The XPS results show that in the Cu2+-ethylenediamine (en)-S2O32− leaching gold system (temperature 25 °C, time 35 h, solution: 0.1 mol/L S2O32−, 5 mmol/L Cu(en)22+, 200 mL solution), the nickel of pyrite-containing nickel can be transferred to the leaching solution and becomes nickel ion. In this leaching system, Cu(II), which was originally complexed with en, is reduced to Cu(I) in a short time. The consumption of Cu(en)22+ increased rapidly in the 5 h period and then decreased gradually after 5 h. The results showed that the presence of free Ni2+ in the solution facilitated the conversion of bivalent copper ions to monovalent copper ions. Free Ni2+ ions can compete with Cu2+ ions for en ligands. When ethylenediamine complexes with Ni2+, the decomposition of Cu(en)22+ into Cu(en)+ and en occurs more rapidly. And the en, which was originally to be oxidized with Cu(en)+ to form Cu(en)22+, forms Ni(en)22+. As a result, the concentration of Cu(en)22+ continues to decrease in a short period of time.

Novel Photobase Generators Derived from Proazaphosphatrane–Aryl Borate for High‐Pressure Mercury Lamp Lithography

AbstractHerein, novel borate‐type photobase generators (PBGs) that generate a proazaphosphatrane known as Verkade's base (2,8,9‐triisobuthyl‐2,5,8,9‐tetraaza‐1‐phosphabicyclo[3.3.3]undecane (TTP)) were developed for photopatterning using a high‐pressure mercury lamp. Eight PBGs were synthesized, each featuring distinct borate substituents: phenyl, p‐fluorophenyl, p‐tolyl, p‐methoxyphenyl, m‐fluoro‐p‐methylphenyl, 4‐biphenyl, 2‐naphthyl, and 6‐methoxy‐2‐naphthyl. The relation between these substituents and their light absorption characteristics was analyzed via ultraviolet–visible spectroscopy and time‐dependent density functional theory calculations. The PBG with the 6‐methoxy‐2‐naphthylborate group (TTP–tetrakis[2‐(6‐methoxynaphthyl)]borate (TTP–TMNB)) demonstrated substantial light absorption near 365 nm (the i‐line of the high‐pressure mercury lamp), generating approximately 60 % of the corresponding TTP in deuterated tetrahydrofuran (THF) upon exposure to 650 mJ/cm2, as confirmed via 1H nuclear magnetic resonance spectroscopy. To evaluate its photolithographic potential, TTP–TMNB was mixed with epoxy resin (jER1001) and a poly(methacrylic acid)‐co‐poly(methyl methacrylate) copolymer (PMA1.6‐co‐PMMA100) in THF. The resulting mixture was spin‐coated onto a silicon wafer and irradiated with the i‐line through a photomask to create a negative‐tone image. The sensitivity and contrast of this photopolymer system were measured to be 45 mJ/cm2 and 1.0, respectively; moreover, a clear 10‐μm negative‐tone resolution was achieved.

Fabrication of hierarchically porous trabecular bone replicas via 3D printing with high internal phase emulsions (HIPEs)

Combining emulsion templating with additive manufacturing enables the production of inherently porous scaffolds with multiscale porosity. This approach incorporates interconnected porous materials, providing a structure that supports cell ingrowth. However, 3D printing hierarchical porous structures that combine semi-micropores and micropores remains a challenging task. Previous studies have demonstrated that using a carefully adjusted combination of light absorbers and photoinitiators in the resin can produce open surface porosity, sponge-like internal structures, and a printing resolution of about 150µm. In this study, we explored how varying concentrations of tartrazine (0, 0.02, 0.04, and 0.08 wt%) as a light absorber affect the porous structure of acrylate-based polymerized medium internal phase emulsions fabricated via vat photopolymerization. Given the importance of a porous and interconnected structure for tissue engineering and regenerative medicine, we tested cell behavior on these 3D-printed disk samples using MG-63 cells, examining metabolic activity, adhesion, and morphology. The 0.08 wt% tartrazine-containing 3D-printed sample (008 T) demonstrated the best cell proliferation and adhesion. To show that this high internal phase emulsion (HIPE) resin can be used to create complex structures for biomedical applications, we 3D-printed trabecular bone structures based on microCT imaging. These structures were further evaluated for cell behavior and migration, followed by microCT analysis after 60 days of cell culture. This research demonstrates that HIPEs can be used as a resin to print trabecular bone mimics using additive manufacturing, which could be further developed for lab-on-a-chip models of healthy and diseased bone.

AIE-derived fluorescent silsesquioxane-based hybrid aerogel for light-enhanced gold recovery

In this work, two aggregation-induced emission (AIE)-active organic fluorescent monomers (TPV, TPC) were synthesized by Knoevenagel reaction of 2,2′-([1,1′-biphenyl]-4,4′-diyl)diacetonitrile with benzaldehyde and 4-bromobenzaldehyde, respectively. Subsequently, two fluorescent hybrid porous polymers with semiconductor performance (PCS-TPV, PCS-TPC) were prepared successfully by connecting octavinyl silsesquioxane (OVS) with TPV and TPC through Friedel-Crafts reaction and Heck coupling, respectively. Among them, PCS-TPV with a hyper-crosslinked structure offered a specific surface area of up to 1165 m2 g−1; PCS-TPC was the first AIE-derived fluorescent hybrid silsesquioxane-based semiconductor polymer with 3-D conjugated structure. Compared with PCS-TPV, PCS-TPC exhibited stronger visible light absorption, higher fluorescent performance and quantum yield due to its high AIE-active unit content. Besides, PCS-TPC exhibited a remarkable gold recovery capacity (Qm = 2728 mg g−1) when exposed to visible light irradiation. Adsorption mechanism revealed that the photoelectrons produced by PCS-TPC under visible light irradiation reduced all adsorbed Au(III) to Au(I) and Au(0). Furthermore, a hybrid aerogel was prepared through physical blending of PCS-TPC with chitosan, overcoming the limitation that insoluble powder was difficult to process and recycle. This work provided a very efficient, sustainable, and industrially feasible way for gold recovery in e-waste.

Iron complexes synthesized from FeOCl with carboxylic acid based ligands as Fenton-like catalysts for the highly efficient degradation of organic dyes over a wide pH range

Iron-based materials have garnered significant attention as Fenton-like catalysts for the degradation of organic dyes. However, challenges remain in optimizing hydroxyl radical (•OH) utilization and broadening the effective pH range for practical applications. In this study, three iron-based catalysts (complex 1, 2, 3) were synthesized via a hydrothermal method, utilizing iron oxychloride (FeOCl) as the metal ion source and 4,5-imidazole dicarboxylic acid, furan-2,5-dicarboxylic acid, and 5-hydroxyisophthalic acid as ligands, respectively. The results indicate that these synthesized Fe-based catalysts exhibit enhanced visible light absorption and superior photo-Fenton activity, outperforming FeOCl in the degradation of rhodamine B (Rh-B), crystal violet (CV), and methylene blue (MB). Moreover, the Fe-based catalyst system operates effectively over a wide pH range (1–8) and efficiently degrades organic dyes. In free radical scavenging experiments, hydroxyl radicals (•OH) and superoxide radicals (•O2-) were identified as the primary agents responsible for photocatalytic degradation. Among the catalysts, complex 1 displayed notable stability, retaining its catalytic activity after three reuse cycles. This work presents a promising approach for designing highly efficient and stable Fenton-like catalysts, offering excellent environmental remediation capabilities across a broad pH range.

In-situ cation-exchange deposited Ag2S/In4SnS8 of Z-type heterojunction coupled with DNA recycling amplification for photoelectrochemical biosensing

Herein, a novel photoelectrochemical (PEC) biosensor was developed utilizing an in situ cation-exchange method to deposit a high-performance Ag2S/In4SnS8, a Z-type heterojunction with co-shared S atoms, as a signal indicator and using DNA recycling amplification for the sensitive and accurate detection of miRNA-141. The photosensitive Ag2S deposited on the In4SnS8 surface not only facilitated the rapid generation of photoelectrons but also formed a Z-type heterojunction with In4SnS8, effectively inhibiting electron-hole pair recombination. This resulted in a considerable improvement in the photoelectric conversion efficiency of Ag2S/In4SnS8, yielding an ∼ 120-fold increase in photocurrent compared to that of In4SnS8 under 660-nm visible-light irradiation. Furthermore, the arborescent DNA structure formed by hybrid chain reaction (HCR) enhanced the steric effect, thereby reducing the PEC response. Importantly, numerous quenchers MnPP competed for light absorption and captured photogenerated electrons in the valence bands of In4SnS8 and Ag2S, reducing electron transfer to the electrode and further considerably reducing the photocurrent. This enabled the sensitive detection of miRNA-141 across a concentration range from 10 amol·L−1 to 100 pmol·L−1, with a limit of detection as low as 3.3 amol·L−1 (S/N = 3). The proposed biosensor exhibits excellent stability and is expected to be applied for detecting clinically relevant disease markers.

Size-dependent competitive effect between surface recombination and self-heat on efficiency droop for 250 nm AlGaN-based DUV LEDs

In this work, electrical and optical performances for 250 nm AlGaN-based flip-chip deep ultraviolet light emitting diodes (DUV LEDs) with different chip sizes are studied. Reduced chip size helps increase the light extraction efficiency (LEE) with the cost of increased surface nonradiative recombination. Nevertheless, a thin p-Al0.67-0Ga0.33-1N layer of 10 nm can manage current distribution while suppressing surface recombination and reducing light absorption simultaneously, which results in the increased optical power density. Thanks to the better current management and reduced optical self-absorption effect, the reduced Joule heating effect suppresses the thermal droop of the optical power density for a small DUV LED chip. We also find that the p-Al0.67-0Ga0.33-1N layer thickness shows very significant impact on device resistance especially for the small DUV LED chip, such that the device resistance has a remarkable increase when the p-Al0.67-0Ga0.33-1N layer is thickened to 100 nm.

Comprehensive analysis of dye adsorption and supramolecular interaction between dyes and cotton fibers in non-aqueous media/less water dyeing system

Cotton textile dyeing consumes large amounts of energy and water and discharges large amount of wastewater and pollutants. Zero or less discharge of the wastewater and contaminants from the cotton textile dyeing has been under high demands from textile industry. Recently, a novel reactive dyeing technology of using a non-aqueous medium with little water (NMLW) was developed for cotton fabrics. However, the use of high concentration of reactive dyes in the system triggers aggregation of the dyes in cotton fibers, influencing the quality of dyed cotton textiles. In this investigation, adsorption, diffusion, and aggregation behavior of reactive dyes in cotton fibers were studied. Compared to traditional water-based dyeing system, cotton fabrics demonstrated superior color depth, as long with higher rates of dye uptake and fixation for reactive dyes. At low dye concentrations, the maximum absorption wavelengths of reactive dyes were unchanged, and complied with the Lambot-Beer law. However, when the dye concentration was excessively high, reactive dyes with different molecular structures, as well as multi-layer dye aggregates with π-π stacking and hydrogen bonding interactions, showed different light absorption spectral characteristics and photophysical properties. Moreover, the dye particle size and dye ionization were influenced by the dye concentration, molecular weight, molecular configuration, etc. Analysis of the molecular dynamics of reactive dyes revealed that the maximum dye aggregation size was predominantly dimer at low dye concentration. However, the dimer ratio significantly decreased, while the trimer ratio increased, and higher-order aggregates were observed at a higher dye concentration. The strength of hydrogen bonds between dye molecules and water molecules, as well as the number of water molecules surrounding dye molecules, was influenced by dye concentration and alkali. This study provides a foundation for understanding the micro-aggregation behavior of reactive dyes and offer guidance for optimizing the dyeing process in practical production settings.

Plasmonic Nanocomposite for Visible Light‐Modulated Bimorph‐Actuator

AbstractSoft actuators have great potential applications in sophisticated movement and sensitive devices due to their flexible nature, good interaction, and precise control. However, existing carbon‐based optical actuators are limited in their response under visible light irradiation. The limited visible light absorbance of the carbon nanostructure brought the metallic nanoparticle into the soft actuators that can absorb visible light. This study introduces a new type of plasmonic photothermal‐bimorph actuator, using graphene oxide (GO), reduced graphene oxide (rGO), and silver nanorods (Ag NRs) to overcome the limitations of traditional optical actuators. The bimorph film is actuated by visible and near‐infrared light stimuli with various power densities showing reversible deformation behavior. The actuator shows significant bending associated with a ≈50° change in bending angle under visible light irradiation with a response time of ≈5 ± 1 sec. Furthermore, a smart photo‐controlled non‐contact switch is fabricated based on photo‐thermal conversion properties, demonstrating perfect integration of plasmonic bimorph actuators. The density functional theory based molecular dynamics calculations provide an additional understanding of the bending of actuators under external stimulus. Using illustrative demonstrations of actuators, these results hint at a method for generating multipurpose visible light‐based soft robots, supporting a new approach to developing an optical locking system.

Synthesis and Binding Properties of High-Affinity Histidine-Bearing Polymers for Wood Lignin.

The pursuit of molecules capable of binding to wood lignin is pivotal for advancing lignin degradation technology, particularly when combined with lignin degradation catalysts. In this study, synthetic polymers bearing histidine moieties, demonstrating remarkable affinity for wood lignin are reported. These polymers, featuring varying degrees of histidine substitution in the form of histidine methyl esters, are synthesized through controlled radical polymerization of an activated ester-bearing monomer, employing a fluorescein-labeled chain transfer agent and subsequent postpolymerization amidation with histidine methyl ester. The binding properties of these histidine-bearing polymers with milled wood lignin under aqueous conditions are investigated. Qualitative assessment of lignin-binding capabilities involve spectroscopic analysis of changes in absorbance of visible light and fluorescence intensity. Furthermore, quantitative evaluation is conducted through surface plasmon resonance measurements to determine the binding parameters of the polymers with wood lignin. Notably, polymers with higher histidine substitution exhibit enhanced binding affinity compared to those with lower histidine substitution levels.

Enhancement in Photodetector Sensitivity Using All‐Inorganic Perovskite Absorber RbGeI3 and Copper Bismuth Thiocyanate for Superior Charge Transport

This study investigates a photodetector design using the nontoxic, all‐inorganic perovskite material RbGeI3, which is distinguished by its efficient light absorption and excellent photoelectric conversion properties. Incorporating copper bismuth thiocyanate (CBTS) and indium gallium zinc oxide layers, this design enhances charge transport, leading to a photodetector that exhibits exceptional sensitivity across the visible spectrum, along with a peak responsivity of 0.63 A W−1 and a detectivity of 1.37 × 1013 Jones in the near‐infrared (NIR) at 900 nm. The proposed photodetector exhibits wide‐spectrum detection, encompassing both the visible range and the NIR region. These results position RbGeI3 and CBTS as compelling alternatives to traditional photodetector materials such as Si‐Ge, InGaAs, ZnO, and GaN. Validation is achieved through simulations using the SCAPS‐1D simulator, underscoring the potential of perovskite materials for advanced photodetector applications.

Engineering Co Single Atoms in Ultrathin BiOCl Nanosheets for Boosted CO2 Photoreduction

AbstractDespite the development of a range of photocatalysts for CO2 reduction, the practical applications are significantly limited by low conversion efficiencies and their reliance on sacrificial agents, which are rooted in thermodynamic and kinetic challenges related to CO2 conversion. Here, the engineering of Co single atoms in ultrathin single‐crystal BiOCl nanosheets for boosted photocatalytic CO2 reduction is reported. The engineering of Co atoms modulates the distribution of photogenerated charges at the catalyst surface, controlling key surface reaction dynamics and suppressing surface electron‐hole recombination. This modulation also improves light absorption and enhances CO2 adsorption and activation, leading to more efficient surface reactions. Notably, CO2 is stably adsorbed onto the (001) face of BiOCl through a Bi‐O‐C(= O)‐Co‐O coordination unit, which lowers the activation energy for CO2 reduction and reduces the formation energy of COOH− intermediates. As a result, the BiOCl photocatalysts achieve a CO formation rate of 183.9 µmol g−1 h−1, when irradiated with a 300 W Xe lamp without cocatalysts or sacrificial agents. It represents an ≈13‐fold increase compared to that of pristine BiOCl, and surpasses most reported Bi‐based photocatalysts to date. Current work provides valuable insights into engineering of single atoms for developing advanced CO2‐reduction photocatalysts.

Theoretical Insights into Ultrafast Separation of Photogenerated Charges in a Push-Pull Polarized Molecular Triad.

Herein, we propose a purely-organic donor-acceptor (D-A) molecular triad, with a light-absorbing polarized molecular wire (PMW) used as a central linkage, as a proof of concept for the possible future applications of the D-PMW-A arrangement in molecular photovoltaics. This work builds upon our earlier study on the PMW unit itself, which proved to be highly promising for the ultrafast photogeneration of free charge carriers. Quantum-chemical calculations performed for the D-PMW-A triad at a semi-empirical level of theory reveal a large electric dipole moment of the system, and show strong charge-transfer (CT) character of its lowest-energy excited electronic states, including the S1, which favours efficient dissociation of an exciton initially formed upon the absorption of light. The confirmation for this effect was found with nonadiabatic molecular dynamics simulations, revealing an ultrafast relaxation from higher, bright excited states to S1, completed on a subpicosecond timescale. The architecture of the proposed molecular triad enables its electronic coupling to the surrounding environment through chemical bonds, or noncovalent stacking interactions, which might open way for synthesis of a new class of D-PMW-A efficient molecular organic photovoltaic materials.

2D Multifunctional Phototransistor Based on MoTe2/Graphene/SnS0.25Se0.75 Heterostructure with High Photogain and Reconfigurable Polarized Detection

Abstract2D van der Waals (vdWs) heterojunctions exhibit facile fabrication process and tunable optoelectronic properties. However, suppressing interfacial charge traps and multifunctional photoresponse remain significant challenges. Here, the study designs a 2D multifunctional phototransistor based on ambipolar MoTe2/graphene (Gr)/p‐type SnS0.25Se0.75 double vdWs vertical heterostructure via alloy engineering. The middle Gr interlayer is pivotal in reducing interfacial charge traps, facilitating vertical photocarrier transportation, and enhancing light absorption coefficient. Under photogating effect, the trapped electrons in SnS0.25Se0.75 promote the photogating effect, resulting in the maximum photogain of 8084 and specific detectivity (D*) of 8.2 × 1012 Jones. Under photoconductive effect, a high responsivity (R) of 36.9 A W−1 and D* of 7.17 × 1011 Jones are achieved. Under photovoltaic effect, the devices exhibit a remarkable R of 501 mA W−1, D* of 1.4 × 1011 Jones. Notably, a self‐driven photocurrent polarized ratio of 8 under 635 nm is achieved because of the anisotropic nature of SnS0.25Se0.75 and the effective double built‐in electric fields. By varying the gate voltage, the polarization ratio can be modulated from 1 to 2.5, enabling reconfigurable polarized‐sensitive detection. Above all, the designed heterojunction with multifunctional and reconfigurable polarization detection.

Computational study of hydrostatic pressure effect on MgSiO3 perovskite oxide for photocatalytic water splitting application

Despite the challenges of developing efficient photocatalysts for water splitting, we demonstrate that MgSiO3 perovskite oxide, under applied external stress, significantly enhances photocatalytic activity. The use of earth-abundant and low-cost photocatalysts for high-efficiency photocatalytic water splitting is extremely important. Using density functional (DFT) calculations, we present increased photocatalytic water splitting activity of MgSiO3 perovskite oxide by applying external stress. Our findings indicate that raising the concentrations of pressure can lower the lattice constants and volume of MgSiO3. An anisotropic elastic material with high stiffness that changes from brittle to ductile at high pressure (10–30 GPa). It is stable under various circumstances owing to its high Debye temperature, thermal conductivity, and melting temperature, all of which are thermodynamic properties. MgSiO₃ is an indirect bandgap (Γ →R) p-type semiconductor with a band gap energy is 2.627 eV at 0 GPa. However, the band gap energies increase as enhanced stress is confirmed by its electronic characteristics, making it appropriate for photocatalytic water-splitting applications. Strong anisotropy, effective light absorption, and reflective properties were revealed by optical investigations, which bode well for photocatalytic applications. Moreover, the optical conductivity suggests its potential for light amplification by showing a gain behavior in the visible light region. Crucially, because of its advantageous band-edge placements, MgSiO₃ shows great promise for photocatalytic water-splitting applications. This work paves the path for more investigation into effective water-splitting technologies by demonstrating the multidimensional properties and novel and inventive nature of MgSiO3 under high pressure, as well as by demonstrating its feasibility for a variety of photocatalytic applications.

Optical absorption studies of pulsed-laser-engineered silver nanospheres and their enhanced catalytic performance in the degradation of toxic methylene blue dye

Pulsed laser ablation in liquid is an environment-friendly and one of the fastest physical routes to synthesize surfactant-free and stable metal/metal oxide nanoparticles with high purity and no harmful residues. In this study, we report the synthesis of silver nanospheres (AgNSs) using the nanosecond pulsed laser ablation in liquid (PLAL) technique resulting in the formation of a colloidal solution. Investigation of the optical properties using UV–Vis spectroscopy revealed the effects of laser wavelength, frequency, fluence, ablation time, and re-irradiation on the light absorption of the produced silver nanospheres. Physicochemical characterizations included FE-SEM, XRD, DLS, FTIR, and XPS techniques to evaluate the size, morphology, crystal structure, size distribution, zeta potential, and surface chemistry. FE-SEM studies revealed the formation of well-dispersed spherical Ag nanospheres with an average particle size of 209 nm without any agglomeration. DLS measurements showed high stability with a recorded zeta potential value of −38.27 (+/−1.81) mV and a wider size distribution. The XRD analysis indicated a face-centered cubic crystal structure with the formation of an oxide layer over the metallic silver core. The presence of silver and oxygen was confirmed through XPS studies with binding energies at 368.1 eV and 374.1 eV and oxide formation on the surface of Ag NSs. Finally, the catalytic activity of the Ag colloid was examined for the degradation of the toxic methylene blue dye. The results revealed an excellent catalytic response with 90 % of the dye degraded in just 15 min of reaction time. The kinetics of the degradation process were studied with a rate constant of 0.054/min−1 showcasing the effectiveness of the pulsed laser-synthesized silver colloidal nanomaterial as a sustainable approach for environmental remediation.

Photocatalytic performance of Ni-Al LDH @Ag2XO4 (X = Cr, Mo, and W) nanocomposites under visible light

The contamination of water sources from dye discharge poses a significant environmental challenge. This study addresses this issue by synthesizing binary composites of Ni-Al LDH@Ag2XO4 (with X=Cr, Mo, and W). The main goal is to increase the separation of charge carriers to boost the efficiency of photocatalysis. The prepared samples were analyzed using FT-IR, FE-SEM, EDS, FE-TEM, XRD, UV–Vis DRS, and XPS techniques. Observations revealed a notable increase in MB degradation through photocatalysis under a 150 W mercury lamp in presence of Ni-Al LDH@Ag2CrO4 compared to individual samples, Ni-Al LDH and Ag2CrO4. At pH= 11, 0.5 g of Ni-Al LDH@Ag2CrO4 shows the highest activity (100 %) for the photodegradation of MB. The absorption edge of Ni-Al LDH@Ag2CrO4 (1.69 eV) has increased compared to that of Ni-Al LDH (2.53 eV), which increases the light absorption capacity. Moreover, the synergistic effect of Ni-Al LDH and Ag2CrO4 increases photocatalytic activity by reducing electron-hole recombination. The proposed Z-Scheme mechanism confirms effective charge separation and increased photocatalytic efficiency.

TiN/TiO2 embedded in ReS2 nanoflowers with wide light absorption and multi-interfacial charge transfer for efficient photocatalytic hydrogen generation

The design of functional materials with efficient light absorption and charge separation is crucial for photocatalytic energy conversion. Herein, a plasmonic TiN/TiO2/ReS2 ternary hybrid is prepared, which exhibits exceptional photocatalytic activity caused by the plasmon-mediated light absorption and multi-interfacial charge separation. The ternary hybrids were synthesized by heating TiN, Re, and S sources at high pressure and temperature. The TiN was partially oxidized to form TiN/TiO2 hybrids, which were then embedded in ReS2 nanoflowers through Ti-S bonds, creating a 3D flower-like structure with multiple interfaces. The plasmon resonance of TiN and the bandgap excitations of ReS2 and TiO2 endow the hybrids with efficient light absorption in UV–VIS-NIR region. Additionally, the novel embedded structure and the multiple interfaces between TiN, TiO2, and ReS2 facilitate the formation of built-in electric fields and multi-channel charge transfer, which efficiently quicken photoinduced carriers’ migration and hot electron injection. Consequently, the TiN/TiO2/ReS2 hybrids demonstrate a high-efficiency photocatalytic hydrogen generation rate, which is 12.1 times that of commercial P25. Notably, the hybrids also exhibit high photocatalytic activity under near-infrared light irradiation. This study offers innovative insights into the design of photocatalysts and suggests that the prepared materials could be utilized in solar-driven energy conversion applications.

The Fabrication of BiVO4/WO3/GaN Heterojunction and its Enhanced Water Splitting Performance

Abstract GaN has garnered significant attention for water splitting due to its excellent light absorption, carrier transport properties, and chemical inertness. However, its bandgap of 3.4 eV restricts absorption to the ultraviolet range. To address this limitation, narrow-bandgap semiconductors BiVO4 and WO3 were deposited on the GaN surface using the sol-gel method. Photoelectrochemical water-splitting tests revealed that the saturated photocurrent densities of GaN/BiVO4 and GaN/BiVO4/WO3 under full-spectrum illumination were 1.42 and 1.86 times greater than that of GaN alone, respectively. This improvement is attributed to the smaller bandgaps of BiVO4 and WO3, which significantly extend the spectral absorption range of GaN. Additionally, BiVO4 and WO3 form heterojunctions through energy alignment, and the built-in electric field at the heterojunctions accelerates the separation of photo-generated carriers, further enhancing energy conversion efficiency. The study also found that the BiVO4 and WO3 films exhibit a 2D flake morphology, providing larger surface areas that enhance light absorption and carrier transport, thereby improving water-splitting efficiency. Our research paves a new path for the application of GaN in water splitting.

Bidirectional "Win-Win": Asymmetrical Nanobowl-Coupled Aggregation-Induced Emissive Nanosilicon-Enhanced Immunochromatographic Strips for the Ultrasensitive Detection of Salmonella typhimurium.

The lack of nanoprobes with an efficient signal response and overlook of cooperation between nanoprobes can be responsible for the unsatisfactory analytical performance of immunochromatographic strips (ITSs). Herein, asymmetrical nanobowl-confined innumerable gold nanoparticles (AuNPs) (AuNPs@AFRNBs) to enhance the light absorption are developed for quenching the fluorescence of aggregation-induced emissive (AIE) nanosilicons, which is used for the construction of a bidirectional complementary-enhanced ITS (BC-ITS) to ultrasensitively detect Salmonella typhimurium (S. typhimurium). Briefly, density functional theory-screened AIEgens with highly fluorescent brightness are confined in nanosilicons, and the nanoconfinement has improved the fluorescent brightness by 6.78-fold compared to the free AIEgens. Moreover, the substituent group effect has also enhanced the fluorescence of the prepared fluorescent nanosilicon by 10,000-fold in ITSs. By virtue of the superior light absorption of AuNPs@AFRNBs, the BC-ITS exhibits a bidirectional "win-win" performance for the sensitive monitoring of S. typhimurium: a "turn-on" mode with a high-brightness colorimetric response and an inverse "turn-off" fluorescence response, whose limits of detection are 364 and 302 CFU mL-1, respectively, which is approximately 100-fold more sensitive than the traditional AuNPs-ITS. Furthermore, the BC-ITS can be successfully used to identify S. typhimurium in milk, illustrating the superiority of the developed BC-ITS in point-of-care diagnosis.