Stable Conversion Research Articles

The distortive effect of organic payments: An example of policy failure in the case of hazelnut plantation

Organic farming is supported in the European Union (EU), among others, via area-based organic payments, targeting better environmental standards, as well as consumers’ demand for organic products. Despite the wide interest growing on hazelnut production in non-traditional production areas in Italy, supply of organic hazelnuts remains negligible. At the same time, evidences show that Italian farmers can receive organic payments, while plantation is not yielding and then either switch to conventional production or continue organic production with no harvest. We employ the annual annuity approach in order to check whether organic payment initiates investments that otherwise would have been unprofitable; and whether it can be exploited by a farmer who has never had intention to produce organic hazelnuts. Results suggest that organic support indeed might be distortive and does not stimulate stable conversion to organic production of hazelnuts. In this regard, we recommend that the current policy should be substantially changed by imposing additional restrictions on conventional or no production or by implying additional requirements for receiving organic payments, for instance at least two subsequent organic contracts.

Light and elevated temperature induced degradation and recovery of gallium-doped Czochralski-silicon solar cells

The fast-firing step commonly applied at the end of solar cell production lines is known to trigger light-induced degradation effects on solar cells made on different silicon materials. In this study, we examine degradation phenomena on high-efficiency solar cells with poly-Si passivating contacts made on Ga-doped Czochralski-grown silicon (Cz-Si) base material under one-sun illumination at elevated temperatures ranging from 80 to 160 °C. The extent of degradation is demonstrated to increase with the applied temperature up to 140 °C. Above 140 °C, the degradation extent decreases with increasing temperature. The degradation of the energy conversion efficiency can be ascribed foremost to a reduction of the short-circuit current and the fill factor and to a lesser extent to a reduction of the open-circuit voltage. The extent of degradation at 140 °C amounts to 0.4%abs of the initial conversion efficiency of 22.1% compared to 0.15%abs at 80 °C. The extent of the efficiency degradation in the examined solar cells is significantly lower (by a factor of ~ 5) compared to solar cells made on B-doped Cz-Si wafers. Importantly, through prolonged illumination at elevated temperatures (e.g. 5 h, 1 sun, 140 °C), an improvement of the conversion efficiency by up to 0.2%abs compared to the initial value is achievable in combination with a permanent regeneration resulting in long-term stable conversion efficiencies above 22%.

High-efficiency yellow-emitting La3Si6N11:Ce phosphor-in-glass for laser-driven white lighting

To cope with the market competition of solid-state lighting, there is an urgent need for an efficient and stable fluorescent conversion material that can be used in high-performance lighting. A novel and unique nitride phosphor, La3Si6N11:Ce3+ (LSN), exhibits a wider luminescence spectrum and better thermal quenching performance than Y3Al5O12:Ce3+ (YAG). In this study, LSN phosphors are dispersed in a SiO2–B2O3–CaO–Na2O glass system, and a series of LSN phosphor-in-glass (LSN PiG) samples are prepared by a low-temperature co-sintering technique. The luminescence, thermal stability, microstructure and photoluminescence properties are investigated. The internal quantum efficiency of LSN:Ce PiG (85%) is close to that of the original phosphor (90%). Under excitation of a 450 nm blue laser diode, the LSN PiG produces white light with a luminescence efficiency of 145.91 lm/W, and a luminous flux of 209lm is achieved. Moreover, the color rendering index of LSN is much higher than that of YAG, reaching 73, indicating that LSN PiGs have good application prospects as yellow converters in high-power laser lighting.

Polysaccharide/Ti3C2Tx MXene adhesive hydrogels with self-healing ability for multifunctional and sensitive sensors

Integrating functionalities such as adhesiveness, self-healing, and conductivity on a polysaccharide-based hydrogel is highly desirable for ever-expanding practical applications, but there is always a challenge. Herein, an elaborately designed nanocomposite hydrogel is fabricated by the addition of highly conductive Ti3C2Tx MXene nanosheets into chondroitin sulfate (CS)/N, N-dimethylamino ethyl acrylate (DMAEA-Q) hydrogel network. Owing to the introduction of sulfonated Ti3C2Tx MXene nanosheets, the as-prepared nanocomposite hydrogels exhibit excellent stretchability (> 5000% strain), rapid self-healing ability (< 60 s), and high adhesiveness (≈ 100 kPa). The proposed hydrogel demonstrates an outstanding electrical conductivity up to 5.33 S/m, allowing real-time monitoring of the bending and stretching movements and full recovery. Furthermore, the SMC hydrogels exhibit fast and stable photothermal conversion performance due to the inherent photothermal behavior. Notably, multifunctional SMC hydrogels present real-time and reversible humidity sensing upon H2O-induced swelling/contraction of nanochannels between the Ti3C2Tx MXene interlayers, enabling respiration monitoring applications.

A Magnetosome-Based Platform for Flow Biocatalysis.

Biocatalysis in flow reactor systems is of increasing importance for the transformation of the chemical industry. However, the necessary immobilization of biocatalysts remains a challenge. We here demonstrate that biogenic magnetic nanoparticles, so-called magnetosomes, represent an attractive alternative for the development of nanoscale particle formulations to enable high and stable conversion rates in biocatalytic flow processes. In addition to their intriguing material characteristics, such as high crystallinity, stable magnetic moments, and narrow particle size distribution, magnetosomes offer the unbeatable advantage over chemically synthesized nanoparticles that foreign protein “cargo” can be immobilized on the enveloping membrane via genetic engineering and thus, stably presented on the particle surface. To exploit these advantages, we develop a modular connector system in which abundant magnetosome membrane anchors are genetically fused with SpyCatcher coupling groups, allowing efficient covalent coupling with complementary SpyTag-functionalized proteins. The versatility of this approach is demonstrated by immobilizing a dimeric phenolic acid decarboxylase to SpyCatcher magnetosomes. The functionalized magnetosomes outperform similarly functionalized commercial particles by exhibiting stable substrate conversion during a 60 h period, with an average space–time yield of 49.2 mmol L–1 h–1. Overall, our results demonstrate that SpyCatcher magnetosomes significantly expand the genetic toolbox for particle surface functionalization and increase their application potential as nano-biocatalysts.

Modeling V̇o2 on-kinetics based on intensity-dependent delayed adjustment and loss of efficiency (DALE).

This study presents and evaluates a new mathematical model of V̇o2 on-kinetics, with the following properties: 1) a progressively slower primary phase following the size-principle of motor unit recruitment, explaining the delayed V̇o2 steady state seen in the heavy exercise intensity domain, and 2) a severe-domain slow component modeled as a time-dependent decrease in efficiency. Breath-by-breath V̇o2 measurements from eight subjects performing step cycling transitions, in the moderate, heavy, and severe exercise domains, were fitted to the conventional three-phase model and the new model. Model performance was evaluated with a residual analysis and by comparing Bayesian (BIC) and corrected Akaike (AICc) information criteria. The residual analysis showed no systematic deviations, except perhaps for the initial part of the primary phase. BIC favored the new model, being 9.3 (SD 7.1) lower than the conventional model whereas AICc was similar between models. Compared with the conventional three-phase model, the proposed model distinguishes between the kinetic adaptations in the heavy and severe domains by predicting a delayed steady-state V̇o2 in the heavy and no steady-state V̇o2 in the severe domain. This allows to determine when stable oxygen costs of exercise are attainable and it also represents a first step in defining time-dependent oxygen costs when stable energy conversion efficiency is not attainable.NEW & NOTEWORTHY We propose and assess a new minimalistic integrated model for the V̇o2 on-kinetics, inspired by the currently available best evidence of the underlying mechanisms. We show that the model provides a similar fit as the conventionally used three-phase model, even though a stricter data fitting method is used for the proposed model. The proposed model clarifies misconceptions related to the V̇o2 slow component's behavior, by clearly predicting that steady-state V̇o2 is attainable in the moderate and heavy exercise intensity domains. Furthermore, the model opens new possibilities for assessing oxygen cost during severe intensity exercise without the fallible assumption of time-constant energy-conversion efficiency.

Effect of Ni-Co bimetallic core-shell catalyst for coke resistance in CO2 reforming of biomass Tar

The deactivation of catalysts due to coke deposition is a major challenge in CO2 reforming of tar technology. The Ni-Co bimetallic catalysts have good resistance to coke deposition for steam reforming of tar, but the performance of for filamentous coking of CO2 reforming of tar is not known. In this work, the effect of Ni-Co bimetallic synergy on the corrosion resistance of filamentous coke was investigated by comparing the catalytic performance of nickel monometallic and Ni-Co bimetallic core-shell catalysts. The Ni8Co@SiO2 catalyst showed efficient and stable hydrogen conversion (62.3–53.3%) and carbon conversion (64.7–56.7%) and excellent resistance to coke deposition with little coke (1.5%) deposition after 300 min of CO2 reforming tar reaction. The Ni8Co@SiO2 was also regenerated for four cycles, demonstrating excellent catalytic activity and recyclability performance. However, as the cobalt content in the Ni-Co bimetal increased, the activity and resistance to coke deposition of the core-shell catalyst decreased due to the increase in size of the Ni-Co alloy and the decrease in the nickel active component. The above results are helpful for the future application of bimetallic core-shell catalyst during CO2 reforming tar.

A Solvothermal Synthetic Environmental Design for High‐Performance SnSe‐Based Thermoelectric Materials

AbstractSnSe is challenging to use in thermoelectric devices due to difficulties in simultaneously optimizing its thermoelectric and mechanical properties. Here, the authors show a unique solvothermal synthetic environmental design to fabricate super‐large and micro/nanoporous Sn0.965Se microplates by using CrCl3. Cl− ions to trigger Sn‐vacancy formation and optimize the hole concentration to ≈3 × 1019 cm−3, while the as‐formed Cr(OH)3 colloidal precipitations act as “templates” to achieve micro/nanoporous features, leading to low lattice thermal conductivity of ≈0.2 W m−1 K−1 in the as‐sintered polycrystal, contributing to a high ZT of ≈2.4 at 823 K and an average ZT of ≈1.1. Of particular note, the polycrystal exhibits high hardness (≈2.26 GPa) and compression strength (≈109 MPa), strengthened by grain refinement and vacancy‐induced lattice distortions and dislocations; while a single‐leg device provides a stable output power (&gt;100 mW) and conversion efficiency of ≈10% by a temperature difference of 425 K, indicating great potential for applying to practical thermoelectric devices.

Coal char gasification for co-production of fuel gas and methane decomposition catalysts

Partial gasification of coal char was conducted with addition of metal oxides for co-production of fuel gas and methane decomposition catalysts. Effect of the metal composition (Ni, Co and Fe based mono- or bi-metals) was investigated on the fuel gas production and the resultant catalyst surface and textural properties, morphology and performance in catalytic methane decomposition (CMD). Besides H2-rich fuel gas production (the combustion energy up to 11.03–23.42 MJ/kgchar) from the gasification, the gasification residue can directly serve as the effective and efficient catalyst for CMD. The Fe and Fe–Co composite oxides were found to be better among the mono- and bi-metallic oxides for the fuel gas production during the gasification, respectively. The Ni-based mono-/bi-metallic catalysts could display high and stable methane conversion (up to 80%) during the 600-min CMD test at 850 °C. Promotional role of the second metal in CMD was discussed on the carbon diffusion, metal mobility and reducibility, formation and growth of the deposited carbons. The formed carbon morphology after CMD was analyzed based on the Kirkendall effect and Tammann temperature and further correlated to the potential catalyst deactivation.

Metal-Organic Framework-Based Nanoheater with Photo-Triggered Cascade Effects for On-Demand Suppression of Cellular Thermoresistance and Synergistic Cancer Therapy.

Nanomedicine with stable light-heat conversion and spatiotemporally controllable drug activation is crucial for the success of photothermal therapy (PTT). Herein, a metal-organic framework (MOF)-based nanoheater with light-triggered multi-responsiveness is engineered to in-situ and on-demand sensitize cancer cells to local hyperthermia. Well-dispersed platinum nanoparticles synthesized inside nanospaces of the MOF are employed as the near-infrared (NIR)-harvesting unit with stable and high light-heat conversion performance. A conformation switchable polymer shell is constructed as a secondary light-responding unit to gate the targeted activation of a molecular inhibitor against thermoresistance. By cascade transformation of light stimuli to downstream signals, the nanoheater enables inhibitor release to go with local heating at the same time restricted in lesion sites to maximize efficacy and minimize systemic toxicity. The efficient photothermal conversion and the blockage of cellular heat-protective pathways provide a dual-mode of action which selectively sensitizes cancer cells to hyperthermia in a spatiotemporally controlled manner. With NIR as the remote switch, the MOF-based nanosystem demonstrates localized and boosted PTT efficacy against cancer both in vitro and in vivo. These results present nanosized MOFs as tailorable and versatile platforms for synergistic and precise cancer therapy.

Round-the-clock bifunctional honeycomb-like nitrogen-doped carbon-decorated Co2P/Mo2C-heterojunction electrocatalyst for direct water splitting with 18.1% STH efficiency

Hydrogen production via solar and electrochemical water splitting is a promising approach for storing solar energy and achieving a carbon-neutral economy. However, hydrogen production by photoelectric coupling remains a challenge. Here, by the cooperative coupling of heteroatoms and a heterojunction interface engineering strategy in a limited space, a honeycomb porous Co2P/Mo2C@NC catalyst was obtained for the first time. In contrast most traditional chemical syntheses, this method maintains excellent electrical interconnections among the nanoparticles and results in large surface areas and many catalytically active sites. Theoretical calculations reveal that the construction of a heterostructure can effectively lower the hydrogen evolution reaction and oxygen evolution reaction barriers as well as improve the electrical conductivity, consequently enhancing the electrochemical performance. Significantly, the overall water-splitting hydrolytic tank assembled using AsGa solar cells enabled the system to achieve a stable solar hydrogen conversion efficiency of 18.1%, which provides a new approach for facilitating large-scale hydrogen production via portable water hydrolysis driven by solar cells.

Nonlinear amplification of the magnetic induction signal in a magnetomodulation sensor with an amorphous ferromagnetic core

The purpose of this work is to show the possibility of using a magnetic field-controlled nonlinearity of the amplitude change in an oscillatory LC-circuit containing a core made of an amorphous ferromagnetic alloy with compensated longitudinal magnetostriction, which makes it possible to obtain a high conversion coefficient of weak magnetic field sensors operating at room temperature. Methods. A practical method for constructing magnetomodulation sensors of magnetic induction with a fixed magnetic displacement field, which corresponds to the maximum steepness of the nonlinear characteristic of an oscillatory circuit with an amorphous ferromagnetic core in the region of autoparametric resonance, is considered. Results. It has been shown that the stable conversion factor of a 35 mm long sensor based on an oscillatory circuit with autoparametric amplification at a modulation frequency of 256 kHz can reach 10 mV/nT, which allows, with the available element base, to record signals of a weak alternating magnetic field with an amplitude of 0.03 pT/Hz1/2 in the frequency range 10...1000 Hz. It is noted that the excitation of the sensor by a weak harmonic magnetic field of a high frequency and the constant presence of the amorphous ferromagnetic core near the state of technical saturation significantly reduces the level of intrinsic magnetic noise of the magnetomodulation sensor. Conclusion. Magnetomodulation sensors with autoparametric amplification of the magnetic induction signal can find application in geophysics, magnetobiology and biomedicine.

Hidden parameters for electrochemical carbon dioxide reduction in zero-gap electrolyzers

The electrochemical reduction of CO 2 from flue gas or direct air capture to relevant syngas mixtures is a promising route toward mitigation of environmental pollution and production of bulk chemicals and fuels. Among the different cell types, gas-fed zero-gap electrolyzers are promising as energy-efficient and scalable devices. We herein investigate the influence of operational parameters related to cathode water management, such as cell orientation, gas humidification, and cathode compression onto CO 2 R. By a stepwise optimization of our not yet fully optimized electrolyzer, stability could be improved by a factor of 3 up to 10 h at 3 V and 300 mA cm −2 . Faradic efficiency for CO after 2 h of electrolysis was increased from 14% to over 60%. Controlling the water management is a key parameter as high water input leads to flooding of the electrodes, whereas lower values decrease the performance of the anion exchange membrane and reduce catalyst wetting. • Water management is a key parameter for efficient CO 2 R • Operational parameters improve the performance of the electrolyzer significantly • Longtime stability can be improved by a factor of 3 Water management in gas-fed electrolyzers is a key parameter toward a stable and efficient conversion of CO 2 to syngas. Hoof et al. herein investigate less commonly studied but crucial operational parameters related to the water management in a CO 2 electrolyzer, including electrolyzer orientation, humidification of the gas stream, and cathode compression.

Smart PdH@MnO2 Yolk-Shell Nanostructures for Spatiotemporally Synchronous Targeted Hydrogen Delivery and Oxygen-Elevated Phototherapy of Melanoma.

Hydrogen therapy, an emerging therapeutic strategy, has recently attracted much attention in anticancer medicine. Evidence suggests that hydrogen (H2) can selectively reduce intratumoral overexpressed hydroxyl radicals (•OH) to break the redox homeostasis and thereby lead to redox stress and cell damage. However, the inability to achieve stable hydrogen storage and efficient hydrogen delivery hinders the development of hydrogen therapy. Furthermore, oxygen (O2) deficiency in the tumor microenvironment (TME) and the electron-hole separation inefficiency in photosensitizers have severely limited the efficacy of photodynamic therapy (PDT). Herein, a smart PdH@MnO2/Ce6@HA (PHMCH) yolk-shell nanoplatform is designed to surmount these challenges. PdH tetrahedrons combine stable hydrogen storage and high photothermal conversion efficiency of palladium (Pd) nanomaterials with near-infrared-controlled hydrogen release. Subsequently, the narrow bandgap semiconductor manganese dioxide (MnO2) and the photosensitizer chlorin e6 (Ce6) are introduced into the PHMCH nanoplatform. Upon irradiation, the staggered energy band edges in heterogeneous materials composed of MnO2 and Ce6 can efficiently facilitate electron-hole separation for increasing singlet oxygen (1O2). Moreover, MnO2 nanoshells generate O2 in TME for ameliorating hypoxia and further improving O2-dependent PDT. Finally, the hyaluronic acid-modified PHMCH nanoplatform shows negligible cytotoxicity and selectively targets CD44-overexpressing melanoma cells. The synergistic antitumor performance of the H2-mediated gas therapy combined with photothermal and enhanced PDT can explore more possibilities for the design of gas-mediated cancer therapy.

Flexible MXene-based Janus porous fibrous membranes for sustainable solar-driven desalination and emulsions separation

Sustainable solar energy driven seawater desalination technology is currently deemed as a promising pathway to overcome the shortage of freshwater resources, but solar water evaporation material suffers from serious salt-fouling, low freshwater yield, and poor long-term performance in seawater. Herein, a Janus photothermal porous fibrous membrane, composed of hydrophobic MXene/Poly(dimethylsiloxane) coatings and a hydrophilic polylactic acid/TiO2 nanofluids porous fibrous membrane, was prepared. During the solar-driven seawater desalination process, the hydrophilic fibrous membrane, functioned as salt-rejection barrier, induced by TiO2 nanofluids and transport seawater to the surface through its microporous channels; the MXene/PDMS coatings acted as a photothermal layer and generated localized heat at the water-vapor interface upon light irradiation. The solar-thermal test results show that, the Janus porous fibrous membrane displays stable solar-thermal conversion efficiency of 60%, freshwater yield of 1 kg m-2 h-1 and low ion concentration (≤1 ppm) under 1 sun irradiation in direct contact mode, which is superior to other literatures reported. With synergistic effect of TiO2 nanofluids and MXene, the Janus fibrous membrane exhibits a high salt rejection rate of 99.95%, and antibacterial activity as high as of 100%. Notably, benefiting from opposite wettability of Janus porous fibrous membrane, the as-prepared membranes also display excellent separation flux and high separation accuracy (>99.95%) in various surfactant-stabilized oil/water emulsions. It is anticipated that this versatility of Janus porous fibrous membrane has excellent photothermal conversion capability and separation properties, making it have great application potential in using sustainable solar energy to collect freshwater from seawater, medical service wastewater and other application in environmental protection.

Expanded graphite/paraffin/silica phase change composites with high thermal conductivity and low permeability prepared by the solid-state wet grinding method

In this study, expanded graphite (EG)/paraffin (PA)/silica (SiO2) composite phase change materials (PCM), with good thermal conductivity and impermeability, were fabricated for potential applications in solar energy. The EG-PA was first prepared by vacuum adsorption and then encapsulated by SiO2 through solid-phase wet grinding in the presence of sodium silicate. Our results show that the EG-PA-SiO2 composite have optimal properties when the mass ratio of raw material is PA: sodium silicate: H2O = 1:9:2:8. The latent heat of melting of the EG-PA-SiO2 composite prepared at this mass ratio is 106.2 J/g. The core material loss ratio, after washing with petroleum ether, is 4.79%. The thermal conductivity is 2.053 W/m·K, which is 8.5 times higher than that of pure paraffin wax, and the melt permeability is 9.35% after 120 min at 60 °C. Under simulated sunlight, the time required for the composite material to change from 30 °C to 65 °C is reduced by 70.78% compared to PA and the heat absorption and release times are nearly unchanged under multiple cycles. These results indicate that the material has a stable photothermal conversion efficiency.

Ammonium-assimilating microbiome: A halophilic biosystem rationally optimized by carbon to nitrogen ratios with stable nitrogen conversion and microbial structure

The contradiction between theoretical metabolism of ammonium assimilation and experiential understanding of conventional biosystems makes the rational optimization of the ammonium-assimilating microbiome through carbon to nitrogen (C/N) ratios perplexing. The effect of different C/N ratios on ammonium-assimilating biosystems was investigated in saline wastewater treatment. C/N ratios significantly hindered the nutrient removal efficiency, but ammonium-assimilating biosystems maintained functional stability in nitrogen conversions and microbial communities. With sufficient biomass, higher than 86% ammonium and 73% phosphorus were removed when C/N ratios were higher than 25. Ammonium assimilation dominated the nitrogen metabolism in all biosystems even under relatively low C/N ratios, evidenced by the extremely low abundances of nitrification functional genes. Different C/N ratios did not significantly change the bacterial community structure of ammonium-assimilating biosystems. It is anticipated that the ammonium-assimilating biosystem with advantages of clear metabolic pathway and easy optimization can be applied to nutrient removal and recovery in saline environments.

Highly selective conversion of mixed polyolefins to valuable base chemicals using phosphorus-modified and steam-treated mesoporous HZSM-5 zeolite with minimal carbon footprint

Catalytic fast pyrolysis of polyolefinic waste streams was investigated to recover valuable base chemicals at high selectivity. HZSM-5 zeolite with different properties, affected by Si/Al, mesoporosity, phosphorus stabilization, and steaming, were tested and thoroughly characterized. Different feeds, catalyst/feed ratios and reaction temperatures were evaluated in a micropyrolysis reactor coupled to two-dimensional gas chromatography. While unmodified HZSM-5 rapidly deactivated, phosphorus-modified and steamtreated HZSM-5 showed almost no deactivation due to its lower coking propensity during 130 runs with stable conversion towards C5+ aliphatics and high C2-C4 olefins selectivity (~75%) using post-consumer mixed polyolefins. The performance of this direct olefins production route with unprecedented high olefin selectivity was further evaluated in a plantwide context. It was found that it requires ~37% lower energy input than the plastics pyrolysis followed by pyrolytic oil steam cracking, while it results to at least a one order of magnitude lower environmental burden as compared to waste incineration.

Triphasic Metal Oxide Photocatalyst for Reaction Site‐Specific Production of Hydrogen Peroxide from Oxygen Reduction and Water Oxidation

AbstractThe search for photocatalysts allowing the highly active, selective, and stable conversion of molecular oxygen into hydrogen peroxide is of worldwide interest. Here, the authors report the efficient conversion of O2 into H2O2 with ≈100% selectivity and stable cycle stability by a triphasic metal oxide photocatalyst with a cobalt hydroxide carbonate nanosheet phase for water oxidation as well as iron oxide and titanium oxide phases of a core‐shell morphology for charge transfer and oxygen reduction, denoted as CFT. The different surface energies of 0.78 (anatase) and 0.93 J m‐2 (rutile) for titanium oxide and 1.39 J m‐2 for iron oxide result in a core‐shell morphology. The band gaps for iron oxide (2.02 eV), titanium oxide (≈3 eV), and cobalt hydroxide carbonate (3.80 eV) sites reveal that the CFT photocatalyst allows visible‐to‐UV light absorption. The 18O2 isotope‐labeling experiments prove that the core‐shell structure promotes hole transfer toward the water oxidation site. Additionally, the hole‐induced H2O2 decomposition at the oxygen reduction site is efficiently hindered. Moreover, the photogenerated electrons transfer toward the oxygen reduction site to produce H2O2 from O2 with ≈10‐fold higher activity than those by conventional single‐ or dual‐phase photocatalysts, while giving robust cycle stability.

0D/3D direct Z-scheme heterojunctions hybridizing by MoS2 quantum dots and honeycomb conjugated triazine polymers (CTPs) for enhanced photocatalytic performance

Herein, a novel direct Z-scheme photocatalyst was accomplished by hybridization of 0D MoS2 quantum dots (MSQDs) and 3D honeycomb-like conjugated triazine polymers (CTP) (namely, CTP-MSQD). The unique 0D/3D hierarchical structure significantly enhanced the exposure of active sites and light harvesting property, while the formed p-n junction enabled the direct strong interface coupling without the necessity of any mediators. The optimized CTP-MSQD3 exhibited continuously increased visible-light-driven photocatalytic activity and strong durability both in Cr(VI) reduction and H2 evolution, featured a rate of 0.069 min−1 and 1070 µmol/(hr∙g), respectively, which were 8 times than those of pure 3D-CTP (0.009 min−1 and 129 µmol/(hr∙g)). We believe that this work provides a promising photocatalyst system that combines a 0D/3D hierarchical structure and a Z-scheme charge flow for efficient and stable photocatalytic conversion.