Enhanced Light Harvesting Research Articles

Polymerized Small‐Molecule Acceptors with Linker Length‐Dependent Photocatalytic Activity for High‐Performance Solar Hydrogen Evolution

AbstractDeveloping organic semiconductor photocatalysts with alterable optical properties and excitonic behaviors for photocatalytic hydrogen evolution has received significant attention recently. Herein, three polymerized small‐molecule acceptors (PSMAs) with different linker lengths, namely PY‐1T, PY‐2T and PY‐3T, are designed and synthesized to construct nano‐photocatalysts. In comparison with small‐molecule YDT, these PSMAs exhibit broader absorption in both visible and near‐infrared (NIR) light region as well as enlarged exciton diffusion length. In the meanwhile, the intramolecular charge transfer and separation in PSMAs is promoted by varying the linker length, leading to enhanced light harvesting and charge utilization. As a result, the single‐component nano‐photocatalyst based on PY‐3T achieves an impressive average hydrogen evolution rate (HER) of 400.3 mmol h−1 g−1 under AM 1.5G sunlight (100 mW cm−2), which is ≈48 times greater than that of YDT NPs (8.3 mmol g−1 h−1). These results not only prove the potential that developing polymerized small‐molecule acceptors with extended chain length as efficient photocatalysts, but also elucidate the importance of regulating linker length in designing high‐performance photocatalysts.

Unraveling Crystal Phase-Driven Activity and Selectivity of WO3 for Photoelectrochemical Biomass Valorization.

Modulating the crystal phase of a photocatalyst significantly impacts its surface and photochemical properties, allowing for the adjustment of catalytic activity and selectivity, particularly in the electrooxidation reactions of biomass-derived chemicals. Herein, monoclinic and hexagonal phases of WO3 are employed as photoanodes for the photoelectrochemical conversion of 5-hydroxymethylfurfural (HMF) to 2,5-diformylfuran (DFF). The monoclinic phase demonstrated exceptional performance in photoelectrocatalytic HMF oxidation, achieving remarkable photocurrent densities (1.1 mA cm-2), which were 5.5 times greater than those observed for hexagonal WO3. Moreover, the yield of DFF products obtained over monoclinic WO3 was approximately 2.5 times higher compared to that of hexagonal WO3. A combination of experiments and theoretical calculations indicates that the superior performance of monoclinic WO3 for HMF oxidation mainly originates from enhanced light harvesting efficiency, better charge separation and utilization, balanced adsorption energy, and stronger oxidative ability of photogenerated holes. This study emphasizes the potential of crystal phase engineering to regulate the reaction activity and selectivity and provides insights into how to design next-generation high-performance photoelectrodes for sustainable chemical production from biomass.

Fabrication of Black Silicon Antireflection Coatings to Enhance Light Harvesting in Photovoltaics

Black silicon has attracted significant interest for various engineering applications, including solar cells, due to its ability to create highly absorbent surfaces or interfaces for light. It enhances light absorption in crystalline solar cells, improving the efficiency of converting incident light into electricity for photovoltaic applications. This research focused on fabricating nanostructures that played a critical role in enhancing light absorption in the upper layers of solar cells. These nanostructures were created using the black silicon method, forming a layer known as “black silicon”. The coating not only improved the efficiency of crystalline solar cells but also enhanced their stability. The antireflection coating, composed of nanostructures with various shapes, including conical, pillar-like, and spike-like forms, achieved a reflectivity as low as 10% in the spectral range of 400–700 nm. This corresponded to a sample with α = 0.85 and a chuck bias of 4 W. An Inductively Coupled Plasma Reactive Ion Etching (ICP RIE) machine was employed to develop and control the specific shape, size, and density of the fabricated black silicon, which was then subjected to testing. The efficiency of the black silicon photovoltaic cell was 23.3%.

Preparation and investigation of 2D/2D black phosphorene/ZnIn2S4 Z‐scheme photocatalysts for enhanced hydrogen evolution

AbstractHeterojunction photocatalytic materials show great promise in hydrogen production from water decomposition under visible light. The selection of components in the heterojunction and the type of heterojunction constructed directly determine the hydrogen production efficiency. In this study, black phosphorene (BP), which has a broad visible light absorption range, and ZnIn2S4 (ZIS), with a suitable band structure, are chosen to design new heterojunction photocatalysts. Through an ultrasound‐assisted solvothermal method, a BP/ZIS heterojunction with a unique layered 2D/2D structure is successfully synthesized. Comprehensive characterization and calculation have elucidated the microstructure and band structure of BP and ZIS, further confirming the formation of a Z‐scheme heterojunction. Such a novel BP/ZIS heterojunction exhibits a remarkable photocatalytic hydrogen evolution rate of 1317 µmol·h−1·g−1, making a 3.35‐fold increase compared to ZIS and superior performance over BP. This enhancement in photocatalytic activity of BP/ZIS heterojunction can be primarily attributed to the enhanced light harvesting and carrier utilization resulting from the formation of the Z‐scheme heterojunction. This work provides new insights for the development of efficient photocatalysts for hydrogen production.

A multiband NIR upconversion core-shell design for enhanced light harvesting of silicon solar cells

Exploring lanthanide light upconversion (UC) has emerged as a promising strategy to enhance the near-infrared (NIR) responsive region of silicon solar cells (SSCs). However, its practical application under normal sunlight conditions has been hindered by the narrow NIR excitation bandwidth and the low UC efficiency of conventional materials. Here, we report the design of an efficient multiband UC system based on Ln3+/Yb3+-doped core-shell upconversion nanoparticles (Ln/Yb-UCNPs, Ln3+ = Ho3+, Er3+, Tm3+). In our design, Ln3+ ions are incorporated into distinct layers of Ln/Yb-UCNPs to function as near-infrared (NIR) absorbers across different spectral ranges. This design achieves broad multiband absorption withtin the 1100 to 2200 nm range, with an aggregated bandwidth of ~500 nm. We have identified a synthetic electron pumping (SEP) effect involving Yb3+ ions, facilitated by the synergistic interplay of energy transfer and cross-relaxation between Yb3+ and other ions Ln3+ (Ho3+, Er3+, Tm3+). This SEP effect enhances the UC efficiency of the nanomaterials by effectively transferring electrons from the low-excited states of Ln3+ to the excited state of Yb3+, resulting in intense Yb3+ luminescence at ~980 nm within the optimal response region for SSCs, thus markedly improving their overall performance. The SSCs integrated with Ln/Yb-UCNPs with multiband excitation demonstrate the largest reported NIR response range up to 2200 nm, while enabling the highest improvement in absolute photovoltaic efficiency reported, with an increase of 0.87% (resulting in a total efficiency of 19.37%) under standard AM 1.5 G irradiation. Our work tackles the bottlenecks in UCNP-coupled SSCs and introduces a viable approach to extend the NIR response of SSCs.

Self-assembled flower-like spherical Bi2WO6/BiOBr S-scheme heterojunction: Improved charge transfer and excellent photocatalytic activity

The suppression of expeditious complexation of photoexcited carriers and the enhancement of light harvesting are two extraordinarily momentous elements for boosting the catalytic activity of synthesized semiconductor photocatalyst. Herein, a sequence of visible-light-induced self-assembled flower-like spherical Bi2WO6/BiOBr S-scheme heterojunctions were successfully fabricated by two-step solvothermal process. The fabricated Bi2WO6/BiOBr hybrids possessed the splendid capacity to catalyze the degradation of bisphenol A (BPA) in water without the addition of surfactant compared to monocomponent photocatalyst. The optimized Bi2WO6/BiOBr (FBBH-16) possessed the most prominent photocatalytic activity, acquiring a conspicuous degradation efficiency of 91.97 % ± 1.51 % for BPA after 60 min illumination. The rate constant k (0.04078 ± 0.0009985 min−1) of FBBH-16, which was approximately 4.0 and 3.5 times that of bare Bi2WO6 and BiOBr, respectively. Such strengthening mechanism was chiefly ascribed to the establishment of S-scheme heterojunction, which efficaciously impeded the complexation of photoexcited charge pairs and noteworthily heightened the light harvesting. Furthermore, the forceful interfacial interactions between Bi2WO6 and BiOBr afforded much more active sites for BPA removal. The quenching experiments confirmed that ·OH and ·O2− are the principal active species for BPA degradation over Bi2WO6/BiOBr hybrids. Ultimately, two possible photodegradation pathways of BPA over Bi2WO6/BiOBr heterojunctions are also come up with on the grounds of the identification of intermediate products. This work furnishes fresh insights into the fabrication of highly efficacious and stable bismuth-based S-scheme heterojunctions for treating the actual wastewater by integrating nanostructure and microscopic morphology.

Optimized design and comparative analysis of double-glazed photovoltaic windows for enhanced light harvesting and energy efficiency in cold regions of China

This study investigates the daylighting performance and energy efficiency optimization strategies of double-glazed photovoltaic windows (DS-STPV) in cold regions of China. By conducting a comprehensive comparative analysis with traditional and energy-efficient window systems, this research aims to identify high-efficiency building solutions tailored to extreme climatic conditions. Amidst the escalating global energy demand and the pressing need for energy conservation and emission reduction, Building-Integrated Photovoltaic (BIPV) technology is increasingly recognized for its potential and value as a critical method for harnessing green energy. However, the widespread adoption of BIPV technology faces several challenges, including cost-effectiveness, conversion efficiency, system stability, and architectural aesthetic integration. Utilizing the T&A House from the 3rd International Solar Decathlon as an empirical case study, this research employs Ecotect and DesignBuilder simulation software to systematically evaluate the daylighting effect and energy performance of DS-STPV. The analysis considers various key design parameters, including photovoltaic cell coverage, window orientation, and window-to-wall ratio. Through refined modeling and multi-dimensional analysis, this study aims to identify the optimal design configurations of DS-STPV windows in cold regions, with the goal of simultaneously achieving superior natural lighting quality and significant building energy efficiency. The findings indicate that a south-facing DS-STPV window design with approximately 30% photovoltaic cell coverage and a window-to-wall ratio of 30% effectively balances daylighting requirements and energy efficiency in cold regions of China. This design strategy not only ensures an abundance of natural light in the room, but also significantly reduces the building’s energy consumption, proving the superior performance of DS-STPV windows in cold climates. In addition, the unique optical properties of DS-STPV windows reduce glare, further improving the overall quality of the indoor environment. In summary, this study provides a robust scientific foundation for the application of DS-STPV windows in cold regions, offering practical guidance and reference for optimizing energy efficiency and facilitating green transformation in future building design.

Tuning the Fe-Gd nanoparticles co-functionalized mesoporous carbon from sphere to nanobowl for advanced bioapplications

Studies on the function-integrated nanocomposites with well-tuned morphologies have received considerable interest. Here, we reported the preparation of mesoporous carbon nanobowl integrated with stoichiometric γ-Fe2O3 and GdPO4 nanoparticles (Fe-Gd/MCN-B) for morphological advantage exploration. Followed by (i) emulsion-induced interface anisotropic assembly of polydopamine, (ii) solvent evaporation-induced sorption of Wells-Dawson-like heterometallic cluster of {Fe6Gd6P6} and (iii) temperature-programmed carbonization, Fe-Gd/MCN-B with the size around 200 nm was isolated. Our in-vitro studies revealed that Fe-Gd/MCN-B showed a 63.0 % amplified photoacoustic (PA) signal intensity as compared with its nanospherical analogue of Fe-Gd/MCN-S owing to the enhanced light harvesting and photothermal conversion on the interface of its nanobowl morphology. Furthermore, the combined magnetic resonance (MR) imagining, drug delivery and photothermal treatment efficacy in Fe-Gd/MCN-B were also validated in-vitro. These results demonstrated that the delicate design of the morphology of function-integrated nanocomposites is an available way for enhanced imaging performance.

A Stable Perovskite Sensitized Photonic Crystal P-N Junction with Enhanced Photoelectrochemical Hydrogen Production.

The slow photon effect in inverse opal photonic crystals represents a promising approach to manipulate the interactions between light and matter through the design of material structures. This study introduces a novel ordered inverse opal photonic crystal (IOPC) sensitized with perovskite quantum dots (PQDs), demonstrating its efficacy for efficient visible-light-driven H2 generation via water splitting. The rational structural design contributes to enhanced light harvesting. The sensitization of the IOPC with PQDs improves optical response performance and enhances photocatalytic H2 generation under visible light irradiation compared to the IOPC alone. The designed photoanode exhibits a photocurrent density of 3.42 mA cm-2 at 1.23 V vs RHE. This work advances the rational design of visible light-responsive photocatalytic heterostructure materials based on wide band gap metal oxides for photoelectrochemical applications.

Computational Study of Moth-Eye Structures for Silicon Solar Cells Lights Harvesting Improvement

Abstract Recently Moth-Eye nanostructure is widely used in solar cell light harvesting enhancement, in this computational work, three different designs; rectangular, triangular, and semi-circular structures were introduced as anti-reflect structures placed above a silicon solar cell, anti-reflected nanostructured modeled and optimized for silicon ultra-thin film solar cells using the finite difference time domain method for optical, and Lumerical devise software for electrical properties study. The effect of the geometrical dimension of the three structures was investigated. It is found that light-harvesting and solar cell performance can be enhanced by choosing a suitable structure and dimension for the suggested structure. The optimum efficiency enhancement achieved was by a semi-circular structure with a radius of 200nm from 8.81% to 11.95%.

Suppressed recombination of a flexible TiO2 nanowires photoanode by coupling of plasmonic Ag nanoparticles in the photoelectrochemical ultraviolet photodetector

The noble metal nanoparticles can improve the efficiency of photoelectric conversion via enhancement of light harvesting for the localized surface plasmon resonance (LSPR) effect. Here, TiO2 nanowires were constructed on carbon fiber cloth as a flexible photoanode for photoelectrochemical (PEC) ultraviolet (UV) photodetector. By decorated noble metal Ag nanoparticles on TiO2 nanowires, the photocurrent was improved from 35.9 μA cm−2 to 268.4 μA cm−2, and the rise and decay time were increased by 0.14 s and 0.12 s, respectively. Moreover, the recombination of photon-generated electrons and holes was also decreased in photoanode due to the Schottky barrier between Ag and TiO2. This work provided an approach to promote the performances of the PEC UV photodetector.

Unlocking Enhanced Light Harvesting in Perovskites: A Light‐Mediated Ligand Management Approach

AbstractInterfaces between nanocrystals and their stabilizing ligands in light‐harvesting devices are crucial for mediating energy transfer, essential for efficient solar energy conversion. In metal halide perovskites, a promising material for these devices, Förster resonance energy transfer (FRET) within perovskite/acceptor‐molecule complexes offers a pathway for optimized energy transfer. However, traditional methods for optimizing FRET in perovskite‐chromophore hybrids are based on static modifications. This study presents an innovative approach for light‐driven dynamic control of FRET, achieving an ≈14% enhancement in efficiency between CsPbBr3 nanocrystals (CPB NCs) and rhodamine B isothiocyanate (RITC) dye. UV light is utilized to reversibly regulate NC‐ligand binding and thus control the coupling between CPB NCs and RITC at their interface. This approach critically relies on strong NC–ligand interactions, such as the Pb─S bond between CPB NCs and RITC. Light exposure weakens the binding of surface ligands, allowing RITC, with its strong bond, to attach more effectively and promote enhanced energy transfer. This light‐activated control is absent with Rhodamine B (RhB) lacking ─NCS group, a strong binding motif. The findings reveal the importance of NC–ligand interactions in dynamically manipulating FRET with light. This pioneering method for nanoscale FRET control paves the way for more efficient light‐harvesting devices.

Preparation of Ag@Au core-shell nanoparticles embedded in TiO2 inverse opal for light harvesting and efficiency enhancement in quantum dot sensitized solar cells

In the fabrication of Quantum dot sensitized solar cells (QDSSCs), it is important to fabricate a photoanode with a high ability to trap photons as well as transfer photogenerated electrons. TiO2 inverse opal (TIO) photonic crystals with their organized porous structures, besides their chemical nature, have unique optical features such as the slow-photon effect, photon localization, and photonic bandgap (PBG). Herein, to improve the efficiency of QDSSCs, gold, silver, and silver/gold core-shell (Ag@Au) plasmonic nanoparticles (nps) are loaded on TIO. The plasmonic nanoparticle-decorated inverse opal improves the light scattering process and provides direct charge transfer tunnels, which can effectively prevent the recombination of electron-hole pairs. In this work, fabricated QDSSCs with TIO (double-layer)/ZnS/CdS/CdSe/ZnSe/ZnS photoanode, and a 6 μm total thickness of the TIO multilayer, has an open circuit voltage (Voc) of 0.745 V and short-circuit current density (JSC) of 16.22 mA/cm2. The obtained results are higher than the common anatase TiO2 (TiO2-A)/ rutile TiO2 (TiO2-R)/QD photoanode. Also, the TIO (double-layer)/Ag@Au/QDs photoanode exhibits JSC=20.3283 mA/cm2, Voc= 0.75 V, and a power conversion efficiency (PCE) of ƞ=10.79 %.

One-Step Self-Assembled WO3/rGO Microspheres Photoanode Assembled Efficient Photocatalytic Fuel Cells for Simultaneous Organic Pollutant Degradation and Electricity Generation.

Photocatalytic fuel cells (PFCs) present a promising and environmentally friendly approach to simultaneously treat organic pollutants in wastewater and electricity generation. The development of photoanodes with high light absorption and carrier mobility is essential for enhancing the performance of PFCs but remains challenging. Herein, a one-step self-assembly strategy was adopted to develop flower-like WO3/rGO microspheres for PFC devices. Attributed to the abundant surface-active sites, enhanced light harvesting, and efficient separation of photogenerated charge carriers, the WO3/rGO photoanode demonstrated superior rhodamine B (RhB) degradation rate (90% in 2 h), maximum power density (4.74 μW/cm2), and maximum photocurrent density (0.096 mA/cm2), 1.4, 2.4, and 4.0 times higher than the corresponding pure WO3 photoanode, respectively. Density functional theory (DFT) calculations reveal that the built-in electric field formed between the interface of WO3 and rGO promotes the transfer of photogenerated electrons from WO3 to rGO, thus exerting a significant impact on improving the migration and separation of photoinduced charge carriers. Moreover, by combining experimental and theoretical results, a complete PFC operation mechanism for the PFC system was proposed. This study focuses on the strategy of constructing rGO-doped photocatalysts to enhance the interfacial charge transfer mechanism, providing a promising approach for the development of high-performance photoanodes in PFC systems.

Gold nanorods as performance enhancers in planar perovskite solar cells: A numerical study

The quest for efficient and sustainable energy sources calls for an optimized optical design in photovoltaic technologies, particularly in perovskite solar cells (PSCs). This study focuses on the numerical analysis of integrating plasmonic non-spherical gold nanorods into realistic n-i-p MAPbI3 PSCs. The research addresses the light-harvesting enhancement, especially in near-infrared (NIR), a known limitation of metal halide PSCs. Nanorods were the selected nanostructures, as their longitudinal plasmon resonance has the potential to cover the NIR spectral limitation. The study aims to optimize the size, aspect ratio, orientation, and distance between nanorods, as well as provide insights into practical solutions for the positioning and encapsulation of the nanorods. The findings reveal that the aspect ratio and orientation of the nanorods significantly impact the absorption enhancement. Optimal outcomes are achieved with the vertical orientation of the nanorods, parallel to the stacking direction of the solar cell films. The most promising results from this study demonstrate that the incorporation of gold nanorods with small aspect ratios close to 1.5 leads to the potential enhancement of the perovskite photocurrent by at least 5 % (for spherical nanoparticles the maximum is 4.4 %). Additionally, it is also possible to reduce the layer thickness and the associated lead amount by at least 33 %, while maintaining the solar cell performance.

Construction of S-scheme NiCoSe2/TiO2 heterojunction for efficient photocatalytic H2 evolution

In this work, TiO2 nanosheets and NiCoSe2 nanoparticles were synthesized via a hydrothermal method respectively, then NiCoSe2 was combined with TiO2 using a solvent evaporation strategy to form heterojunction for efficient photocatalytic H2 evolution. The investigation demonstrates that the H2 evolution rate of 5 %-NiCoSe2/TiO2 can reach up to 4976 μmol·g−1·h−1 in the sacrificial agent of 20 vol% triethanolamine (TEOA) solution under a 300 W Xe lamp irradiation, which is approximately 35.5 times higher than that of TiO2 (140 μmol·g−1·h−1). Besides, the composite exhibits excellent stability after undergoing five consecutive cycles. The prominent H2 evolution activity of this system can be attributed to the abundant redox active sites provided by the bimetallic selenides, as well as the enhanced light harvesting ability and photocurrent response, reduced electrochemical impedance especially the improved electron-hole (e--h+) pairs separation due to the formed S-scheme charge transfer route between TiO2 and NiCoSe2.This work demonstrates the promising application potential of bimetallic selenides in photocatalytic H2 evolution.

Defect-mediated Fermi level modulation boosting photo-activity of spatially-ordered S-scheme heterojunction

Spatially-ordered S-scheme photocatalysts are intriguing due to their enhanced light harvesting, spatially isolated redox sites, and strong redox abilities. Nonetheless, heightening the performance of S-scheme photocatalysts via controllable defect engineering is still challenging to now. In this work, multi-armed MoSe2/CdS S-scheme heterojunction with intimate Mo-S bond coupling and adjustable Se vacancies (VSe) and Mo5+ concentrations was constructed, which consisted of few- or even single-layered MoSe2 growing on the {11–20} facets of wurtzite CdS arms. The S-scheme charge transmission mechanism of MoSe2/CdS heterojunction was validated by density functional theory calculation combined with in situ photo-irradiated X-ray photoelectron spectroscopy, surface photovoltage, and radical measurements. Moreover, the Fermi level gap between CdS and MoSe2 was enlarged by regulating the contents of donor (VSe) and acceptor (Mo5+) impurities with synthesis temperature, which strengthens the built-in electric field and carriers transfer driving force of MoSe2/CdS composites, contributing to an outstanding H2 evolution activity of 52.62 mmol·g−1·h−1 (corresponding to an apparent quantum efficiency of 34.8 % at 400 nm) under visible-light irradiation (λ > 400 nm), 25.8 times that of Pt-loaded CdS counterpart and a substantial amount of reported CdS-containing photocatalysts. Our study results are anticipated to facilitate the rational design of advanced semiconductor nanostructures for efficient solar conversion and utilization.

Enhanced light harvesting ability in hollow Pt/TiO2 nanoreactor for boosting tetracycline photodegradation

Utilizing solar energy to decompose tetracycline (TC) is a green strategy to treat wastewater. Herein, a heterogeneous hollow structured TiO2 decorated Pt nanoparticles were successfully designed and synthesized via hard-template approach and photo-deposition process toward TC photodegradation. The Pt nanoparticles loaded on the surface of hollow structured TiO2 can increase the visible light absorption due to the local surface plasmon resonance (LSPR) effect. Furthermore, owing to the tough electron oscillation of the LSPR excitation, the plasmonic hot holes on the surface of Pt nanoparticles can capture the electrons of TiO2, effectively facilitating the separation of photo-excited charge carriers because of the formation of Schottky junction constructed between Pt and TiO2. Combined the natural merits of shorten conveying path of charge carriers and physical structural stability for hollow structure, the optimal Pt/TiO2 hetero-junction hybrid showed superior photocatalytic activity and durability for TC photodegradation with the degradation efficiency of 93.8 ​% after 30 ​min and the rate constant of 0.09196 min−1 under 300 ​W Xe lamp irradiation. This work displays a heterogeneous hybrids catalyst based on eco-friendly metal and semiconductor materials which can be used in the fields including without limitation TC photodegradation.

Electrospinning mediated solvothermal preparation of hierarchical MGa2O4/ZnIn2S4 (M = Ni, Co) hollow nanofibers with p-n heterojunction for boosting photocatalytic H2 evolution

ZnIn2S4 has been extensively studied in the field of photocatalytic hydrogen evolution (PHE), but its bulky structure often results in high charge carrier recombination and low light harvesting capability. Herein, efficient hierarchical MGa2O4/ZnIn2S4 (M = Ni, Co) hollow nanofiber photocatalysts with p-n heterojunction were fabricated by an electrospinning-solvothermal method. The hierarchical structure of MGa2O4/ZnIn2S4 composites has facilitated p-n heterojunction formation, promoted the charge separation efficiency, enhanced light harvesting capability, and provided abundant reactive sites. The synergistic effects of MGa2O4 and ZnIn2S4 accelerated the PHE rate by reducing the *H reaction intermediates energy barrier. Under simulated solar light, the NiGa2O4/ZnIn2S4 and CoGa2O4/ZnIn2S4 with optimal proportions delivered outstanding PHE rate of 9292 and 6283 µmol·g−1·h−1, which was 5 and 3 times higher than that of pure ZnIn2S4, respectively. This work opens up an efficient electrospinning-mediated solvothermal strategy for constructing hierarchical ZnIn2S4-based nanofiber composites with excellent PHE performance.

Super-Assembled Multilayered Mesoporous TiO2 Nanorockets for Light-Powered Space-Confined Microfluidic Catalysis.

In the field of sustainable chemistry, it is still a significant challenge to realize efficient light-powered space-confined catalysis and propulsion due to the limited solar absorption efficiency and the low mass and heat transfer efficiency. Here, novel semiconductor TiO2 nanorockets with asymmetric, hollow, mesoporous, and double-layer structures are successfully constructed through a facile interfacial superassembly strategy. The high concentration of defects and unique topological features improve light scattering and reduce the distance for charge migration and directed charge separation, resulting in enhanced light harvesting in the confined nanospace and resulting in enhanced catalysis and self-propulsion. The movement velocity of double-layered nanorockets can reach up to 10.5 μm s-1 under visible light, which is approximately 57 and 119% higher than that of asymmetric single-layered TiO2 and isotropic hollow TiO2 nanospheres, respectively. In addition, the double-layered nanorockets improve the degradation rate of the common pollutant methylene blue under sustainable visible light with a 247% rise of first-order rate constant compared to isotropic hollow TiO2 nanospheres. Furthermore, FEA simulations reveal and confirm the double-layered confined-space enhanced catalysis and self-propulsion mechanism.