Search

A 3D α-MoO3 nanostructure for high-performance triethylamine (TEA) detection was synthesized via the facial oxidation of MoS2 nanoflowers (NFs) obtained by a hydrothermal process. The influence of the time of hydrothermal process in growing MoS2 on the morphologies of the final MoO3 obtained after calcination was investigated. As-obtained MoO3 and their precursors were systematically characterized by various techniques, such as X-ray diffraction, Raman, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, and N2 adsorption–desorption isotherms. Results showed that MoO3 with a hierarchical layered nanostructure was successfully obtained. After hydrothermal treatment of the MoS2 precursor for 20 h, the typical MoO3-based sensor (called M20) exhibited a high response of 2.42 at a very low TEA concentration of only 0.1 ppm at 240 °C. The M20 sensor response to 50 ppm TEA was as high as 125 with a fast response/recovery time of 14/22 s. Moreover, the sensor had a high stability and reproducibility as well as a high selectivity against other interfering VOCs or gases. Due to the tendency of TEA to adsorb to active oxygen sites of MoO3, the enhanced sensing properties of MoO3 can be ascribed to the remarkable hierarchical structure and large surface area. MoO3 obtained after calcination of hydrothermally grown MoS2 is thus a promising sensing material for enhanced TEA gas detection.

Defect engineering is an important strategy to regulate electronic structure of electrocatalysts for electrochemical N2 fixation, aiming at improving the electron state density and enhancing the adsorption and activation of inert N2. In this paper, a high-temperature strategy to anneal the natural molybdenite under Ar atmosphere was developed, and the as-obtained molybdenite with S vacancies boosted a high activity for N2 reduction reaction. In 0.1 M HCl, the catalyst annealed at 800 °C exhibits a high Faradic efficiency of 17.9% and a NH3 yield of 23.38 μg h−1 mg-1cat. at −0.35 V versus reversible hydrogen electrode, two times higher than that of the pristine molybdenite. The facile one-step annealing method introduces the defects (e.g., S vacancies) in the surface of the natural molybdenite particles to prepare catalysts for generating ammonia by reducing nitrogen at room temperature under ordinary pressure, promoting the development of low-carbon economic prospect.

Acetone sensors with high response and excellent selectivity are of enormous demand for monitoring the diabetes. This paper has reported a novel porous 3D hierarchical Co3O4/rGO nanocomposite synthesized by a microwave-assisted method, by which Co3O4 nanoparticles are rapidly and uniformly anchored on rGO nanosheets. The phase composition, surface morphology of the Co3O4/rGO composites and the effect of rGO on their acetone-sensing performance were systematically investigated. The results show that the sample with an optimized content of rGO (Co3O4/rGO-1) achieves the highest stability and response to acetone (0.5 ~ 200 ppm) at a relatively low temperature (~160 °C). Also, the Co3O4/rGO-1 exhibits a high acetone-sensing selectivity against the gases (or vapors) of H2S, H2, CH4, HCHO, CH3OH, C3H8O and C2H5OH. The enhanced acetone-sensing performance of the Co3O4/rGO composite can be attributed to the Co3O4/rGO p-p heterojunction and the Co3+−C coupling effect between Co3O4 and rGO, improving transport of carriers. In addition, the unique 3D hierarchically porous structure and large surface areas are favorable to adsorption and desorption of gas molecules. This facile microwave-assisted method provides a charming strategy to develop smart rGO-based nanomaterials for real-time detection of harmful gases and rapid medical diagnosis.

Lithium–sulfur batteries (LSBs) are a class of new-generation high-energy-density rechargeable batteries. However, the persisting issues of lithium polysulfide (LiPS) dissolution and shuttling severely impedes their practical applications. To address this challenge, we synthesized hierarchical porous carbon nanonet flakes (CNNFs) decorated with a small amount of loosely distributed MoS₂, as an effective interlayer for LiPSs stabilization. Due to the special hierarchical porous structures with large abundant micro-, meso-, and macro-pores derived from the linear-PEI-templated CNNFs and the chemisorption and electrocatalytic effects for MoS₂, the shuttling of the soluble polysulfides intermediates is efficiently alleviated, accompanied by a stabilized Li⁺ transportation pathway for the cell. A high initial capacity of 1413.8 mA h·g–¹ at 0.1 C and a stable capacity of 897.5 mA h·g–¹ at 0.5 C after 200 cycles are obtained, corresponding to a capacity decay rate of 0.063% per cycle. Moreover, after 500 cycles at 1 C, a discharging capacity of 515.7 mA h g–¹ with a Coulombic efficiency of 98.7% can be obtained. The trapping of polysulfides and the synergistic maintenance of electron and ion pathway can provide an effective stabilization strategy for high-performance lithium–sulfur battery.

Constructing a befitting structure for efficient charge separation and transport is highly required for photocatalytic water splitting reactions to generate hydrogen (H2). Herein, we successfully integrated a defective TiO2/MoP heterojunction with highly conductive carbon cloth (CC), for constructing a panel reactor with charge transfer channels to boost H2 evolution. As expected, the behavior of photogenerated charge carriers is effectively steered, resulting in high-efficiency charge migration and separation, and consequently improving photocatalytic activity. The optimal TiO2/MoP/CC exhibits a H2 generation rate of 14.7 μmol h−1 cm−2, up to 19 times higher than that of TiO2/CC. Our work can open up ways to optimize the photocatalytic performance by developing novel non-powder-based photocatalyst systems with good stability and recyclability.

A single-crystalline defect-less phosphor is desired for efficient luminescence of the therein doped optical activators. In this paper, microsized MgAl2O4:Mn4+ single-crystal phosphors with bright red luminescence were grown in molten LiCl salt at 950 °C, for application in blue LED pumped white lighting. By comparing the phosphor formation from various Mg2+- and Al3+-bearing sources, both the template-formation and the dissolution-diffusion processes were evidenced to account for the formation of the microsized MgAl2O4:Mn4+ crystallites. Using nano γ-Al2O3 as the Al3+-bearing precursor, the uniform MgAl2O4:Mn4+ microcrystallites with a {111} planes-exposed tetragonal bipyramid morphology were obtained. The photoluminescence property was studied at various temperatures, and Mg ↔ Al anti-site disorder induced luminescence broadening was discussed. The Mn4+ 2Eg → 4A2g transition in MgAl2O4 shows a quite short luminescence wavelength peaking at 651 nm and ultrabroadband emission extending to 850 nm. The luminescence is relatively robust against thermal effect with relatively high thermal quenching temperature of 400 K and activation energy of 0.23 eV. Employing the red-emitting MgAl2O4:Mn4+ crystallites, blue LED pumped white lighting prototypes were fabricated which simulate the solar-like spectrum and show neutral to warm white.

A precursor-engineering strategy coupled with a microwave molten-salt process (PE-MWMS) is developed to synthesize graphitic carbon nitride (g-C3 N4 ) with an isotype triazine/heptazine-based g-C3 N4 heterojunction as a photocatalyst for the hydrogen evolution reaction (HER) under visible light illumination. Four hybrid precursor combinations-thiourea/melamine, thiourea/dicyandiamide, urea/melamine, and urea/dicyandiamide-are used to synthesize g-C3 N4 heterojunctions by the PE-MWMS process. Control experiments indicate that the precursor components and microwave treatment have a great effect on the HER performance of the g-C3 N4 samples. Samples synthesized with the optimal molar ratios of thiourea/melamine (2:1), thiourea/dicyandiamide (2:1), urea/melamine (3:1), and urea/dicyandiamide (3:1), exhibit the highest HER rates of 3135, 2519, 2844, and 2565 μmol g-1 h-1 , respectively. The amounts of heptazine and triazine units in the g-C3 N4 samples can be easily adjusted by changing the ratios of the hybrid precursors and play a decisive role in improving the photocatalytic HER activity. Because of the unique composition and microstructure, the efficient separation of electron-hole pairs, the broadened photo-absorption edges, and the narrowed band gaps, the as-obtained triazine/heptazine-based g-C3 N4 nanostructures exhibit promising activity for HER application.

Building architectures to manipulate light propagation using a light-conversion matrix is one of the most competitive strategies to enhance photocatalytic performance. In this work, a bio-inspired SiO2 hard template with interconnected SiO2 with a one-dimensional structure was devised to enhance the visible light harvesting ability of g-C3N4, and the SiO2/g-C3N4 nanocomposite is cleverly synthesized via an in situ thermal polymerization method. Based on UV-vis diffuse reflectance spectrometry (UV-vis DRS) and finite difference time domain simulation (FDTD) measurements, it is found that the SiO2/g-C3N4 nanocomposite displays obviously enhanced visible light absorption and light-scattering when compared to pristine g-C3N4, suggesting it has highly enhanced light harvesting ability. As expected, SiO2/g-C3N4 displays a remarkable enhancement in photocatalytic H2 production when compared to bare g-C3N4. Such enhancement is attributed to the synergistic effect of g-C3N4 and SiO2 hard template microstructures. The SiO2 one-dimensional structure not only enhances light scattering to widen the visible-light absorption range and improve the utilization efficiency of solar energy, but it also increases the specific surface area of g-C3N4 by reducing its aperture size. This research has far-reaching implications for increasing the use of sunlight and improving the development of hydrogen energy.

Adsorption and photocatalytic degradation are effective strategies to purify the wastewater caused by organic dyes. In this study, graphitic carbon nitride (g-C3N4) powders are prepared from melamine with a thermal decomposition method, which are applied to synthesize the direct Z-scheme g-C3N4-ZnO@graphene aerogel (g-C3N4-ZnO@GA) heterojunctions with a hydrothermal self-assembly combined with freeze-drying. As adsorbents and photocatalysts, the heterojunctions exhibit superior adsorption capacity and catalytic activity for the elimination of organic pollutants irradiated by UV and visible light. Among all the materials, g-C3N4-ZnO@GA(30%) displays the best purification efficiencies of rhodamine B (RhB) under both UV and visible light illumination, reaching 81.0% and 82.7%, respectively, because of its hierarchical porous structure and the synergistic effect among the components. More importantly, g-C3N4-ZnO@GA(30%) possesses good reusability, which can keep 87.1% of the initial activity after four cycles. What's more, the heterojunctions also demonstrate high removal efficiency for other organic dyes, such as methyl orange (MO), demonstrating their promising application in environmental remediation. Finally, based on the experimental investigations, a reasonable photocatalytic mechanism is proposed and analyzed. The present work provides a promising way to construct the direct Z-scheme porous heterojunctions for elimination of environmental pollutants.

Designing an architecture with the ability to temporarily capture one kind of charge carrier has a critical role to play in enhancing the performance of photocatalytic reactions. Here, we report that SrTiO3 nanofibers that have been treated with a brief method of H2 calcination in an H2/N2 atmosphere (denoted as STO-NH) form oxygen vacancies (OVs) and achieve significant improvement in performance in photocatalytic H2 production without the presence of cocatalysts. These OVs can trap photogenerated electrons, which inhibits the recombination of electrons and holes in both the surface and the bulk, thus improving the photocatalytic decomposition of water. Moreover, the concentration of surface OVs in STO-NH presents volcanic characteristics: the increase with rise in hydrogenation temperature, with a consequent increase in catalytic activity, indicates well-controlled formation of OVs. The existence and concentration of the OVs in STO-NH photocatalysts are investigated qualitatively through electron paramagnetic resonance, high-resolution transmission electron microscope and photoluminescence emission spectra. A reasonable photocatalytic mechanism is proposed that we expect to be able to provide significant guidance for future study.

Acetone sensors with high response and excellent selectivity are of enormous demand for monitoring the diabetes. This paper has reported a novel porous 3D hierarchical Co

Focused ultrasound (FUS) is a potential tool for treating chronic pain by modulating the central nervous system. Herein, we aimed to determine whether transcranial FUS stimulation of the anterior cingulate cortex (ACC) effectively improved chronic pain in the chronic compress injury mice model at different stages of neuropathic pain. The mechanical threshold of pain was recorded in the nociceptive tests. We found FUS stimulation elevated the mechanical threshold of pain in both short-term ( p < 0.01 ) and long-term ( p < 0.05 ) experiments. Furthermore, we determined protein expression differences in ACC between the control group, the intervention group, and the Sham group to analyze the underlying mechanism of FUS stimulation in improving neuropathic pain. Additionally, the results showed FUS stimulation led to alterations in differential proteins in long-term experiments, including cellular processes, cellular signaling, and information storage and processing. Our findings indicate FUS may effectively alleviate mechanical neuropathic pain via the ACC’s stimulation, especially in the chronic state.

A single-crystalline defect-less phosphor is desired for efficient luminescence of the therein doped optical activators. In this paper, microsized MgAl

Background: Non-small cell lung cancer (NSCLC) is the most common malignant tumor, and its recurrence and metastasis are the main causes of death. Recently, there are evidences that tumor derived exosomes play an important role in the occurrence and development of non-small cell lung cancer.Material/Methods: First, miR-185-5p and RAB35 expression in tumor tissues, paracancerous healthy tissues, lung cancer cell lines and normal bronchial epithelial cell line were detected. Then, miR-185-5p and RAB35 were over-expressed/knocked down to study their effects on A549 cells and H2170 cells proliferation, migration and invasion . Next, bioinformatics analysis and luciferase reporter gene analysis verified the targeting relationships of miR-185-5p and RAB35 , respectively. Finally, the exosomes secreted by tumor cells with RAB35 gene downregulated or miR-185-5p overexpression were co cultured with their parent cells to verify the regulatory effect of RAB35 on the secretion and function of exosomes.Results: The miR-185-5p expression was downregulated, while RAB35 expression was prominently upregulated in NSCLC tissues and cell lines. Moreover, miR-185-5p overexpression or RAB35 downregulated suppressed cells proliferation, migration and invasion. Furthermore, we clarified that RAB35 was a direct target of miR-185-5p. Additionally, exosomes derived from tumor cells could restore cells proliferation, migration and invasion, while exosomes secreted by tumor cells with RAB35 downregulated or mR-185-5p overexpression lose the ability to restore cells proliferation, migration and invasion.Conclusions: Our findings indicate that miR-185-5p targets RAB35 gene to regulate tumor cell-derived exosomes-mediated proliferation, migration and invasion of NSCLC cells.

Quick capacity loss due to the polysulfide shuttle effects is a critical challenge for high-performance lithium&ndash, sulfur (Li&ndash, S) batteries. Herein, a novel 2D/1D V2O5 nanoplates anchored carbon nanofiber (V-CF) interlayer coated on standard polypropylene (PP) separator is constructed, and a stabilization mechanism derived from a quasi-confined cushion space (QCCS) that can flexibly accommodate the polysulfide utilization is demonstrated. The incorporation of the V-CF interlayer ensures stable electron and ion pathway, and significantly enhanced long-term cycling performances are obtained. A Li&ndash, S battery assembled with the V-CF membrane exhibited a high initial capacity of 1140.8 mAh&middot, g&minus, 1 and a reversed capacitance of 1110.2 mAh&middot, 1 after 100 cycles at 0.2 C. A high reversible capacity of 887.2 mAh&middot, 1 is also maintained after 500 cycles at 1 C, reaching an ultra-low decay rate of 0.0093% per cycle. The excellent electrochemical properties, especially the long-term cycling stability, can offer a promising designer protocol for developing highly stable Li&ndash, S batteries by introducing well-designed fine architectures to the separator.

Quick capacity loss due to the polysulfide shuttle effects is a critical challenge for high-performance lithium–sulfur (Li–S) batteries. Herein, a novel 2D/1D V2O5 nanoplates anchored carbon nanofiber (V-CF) interlayer coated on standard polypropylene (PP) separator is constructed, and a stabilization mechanism derived from a quasi-confined cushion space (QCCS) that can flexibly accommodate the polysulfide utilization is demonstrated. The incorporation of the V-CF interlayer ensures stable electron and ion pathway, and significantly enhanced long-term cycling performances are obtained. A Li–S battery assembled with the V-CF membrane exhibited a high initial capacity of 1140.8 mAh·g−1 and a reversed capacitance of 1110.2 mAh·g−1 after 100 cycles at 0.2 C. A high reversible capacity of 887.2 mAh·g−1 is also maintained after 500 cycles at 1 C, reaching an ultra-low decay rate of 0.0093% per cycle. The excellent electrochemical properties, especially the long-term cycling stability, can offer a promising designer protocol for developing highly stable Li–S batteries by introducing well-designed fine architectures to the separator.

Construction of functional photocatalysts with ultrahigh photocatalytic hydrogen evolution using solar energy is still a serious challenge for scientific researchers. Here, recently, a facile chemical reduction method is developed to synthesize NixCo1-x/Zn0.75Cd0.25S nanohybrid photocatalysts, a kind of promising smart material with optimizing H2 evolution rate being 0.21 mol h−1 g−1 under simulated solar light irradiation with an apparent quantum efficiency (AQE) of 13.3% at 365 nm, an ultrahigh H2 evolution rate among almost all the semiconductor-based photocatalysts. More importantly, the NixCo1-x/Zn0.75Cd0.25S photocatalyst shows a sufficient stability property for >20 h. The pronounced synergistic effect between non-noble-metals of Ni and Co boosts the transfer and separation of photo-generated electron-hole pairs, and a synergistic catalytic mechanism has been proposed and studied in detail.

In artificial photocatalysis for hydrogen (H2) generation from water reduction, low apparent quantum efficiency (AQE) always confines the photocatalytic conversion efficiency. Here, we demonstrate a new strategy for the design and synthesis of one-dimensional (1D) SrTiO3@Mo2C core-shell nanostructure for highly enhanced photocatalytic H2 generation activity. The thin nanolayer of Mo2C improves the interfacial conductivity, facilitates transport of photo-generated charge carriers as well as prolongs charge carriers’ lifetime, that minimizing the recombination of photo-generated electrons and holes. Thus SrTiO3@Mo2C hybrid achieves drastically enhanced photocatalytic H2 generation rate up to 7.93 mmol h−1 g−1 with respect to the pristine SrTiO3 (0.53 mmol h−1 g−1) in a solar-driven reaction system, with an AQE of 29.3% at 313 nm. The charge carrier dynamics based mechanism was further confirmed by analysis of time-resolved photoluminescence (TRPL), surface photovoltage (SPV), transient photovoltage (TPV), open circuit potential (OCP) decay curves as well as the electrochemical impedance spectroscopy (EIS) measurements. It is unambiguously to demonstrate that Mo2C is a highly active cocatalyst to dramatically boost the charge separation for photocatalytic water reduction.

The construction of integrated heterojunction system photoelectrodes for solar energy conversion is indubitably an efficient alternative due to their effectiveness in charge separation and optimizing the ability for reduction and oxidation reactions. Here, an integrated photoanode constructed with carbon quantum dot (CQD) sensitized Ti:Fe2O3@GCNN (where GCNNs are graphitic carbon nitride nanosheets) core–shell nanoarrays is demonstrated, showing an excellent photocurrent density as high as 3.38 mA cm−2 at 1.23 V versus a reversible hydrogen electrode (VRHE), 2-fold higher than that of pristine Ti:Fe2O3, which is superior over that of recently reported promising photoanodes. In this ternary system (Ti:Fe2O3@GCNN-CQDs), each component plays a specific role in the process towards superior PEC water oxidation: (i) the vectorial hole transfer of Ti:Fe2O3 → g-C3N4 → CQDs; (ii) the introduction of CQDs leads to high catalytic activity for H2O2 decomposition contributing a high rate activity for water oxidation via a two-step-two-electron water-splitting process; (iii) the favorable electron transport behavior of CQDs. This controlled structure design represents one scalable alternative toward the development of photoanodes for high-efficiency water splitting.

Owing to the high theoretical photocurrent density, the hematite (α-Fe2O3) based photoanode has been intensively concerned in photoelectrochemical (PEC) water splitting, but its serious charge recombination and sluggish water oxidation kinetics are still the stumbling blocks. This work reports a high-performance Fe2O3-based photoanode achieved by coating multifunctional FeCo-bimetal organic framework (MOF) nanolayers (NLs) on Fe2O3 nanoarrays via an in-situ solvothermal process. The FeCo MOF NLs introduced not only effectively passivate the surface states of Fe2O3 photoanode and boost the water oxidation kinetics serving as the cocatalyst, but also construct p-n heterojunctions with Fe2O3 to accelerate the directional migration and separation of photogenerated charge carriers. Expectedly, the as-obtained FeCo-MOF/Fe2O3 photoanode exhibits an apparent negative shift of onset potential, an excellent long-term PEC stability, and highly improved photocurrent density. This finding provides a novel and effective strategy to introduce advanced multifunctional surface coating for enhancing the PEC performance of photoelectrodes.

Efficient metal-free catalysts for oxygen evolution reaction (OER) are challenged for enhancing the efficiency of water electrolysis. Here, an extremely simple one-step calcination route is put forward to synthesize free-standing N-doped C electrocatalyst for the OER. The incorporation of N into carbon cloth (CC) can tune the electronic structure around the C sites for enhancing the reaction active sites and electrical conductivity, and optimizing adsorption energies for intermediates. As expected, the as-prepared CC-9NH3-3h electrode demonstrates remarkable OER performance in alkaline medium, affording an extremely low overpotential of 298 mV (@10 mA cm−2) and Tafel slope of 62 mV dec−1, which is comparable to that of a commercial RuO2 and other promising metal-based OER catalysts. Our findings provide opportunities to explore CC as a new class of self-supporting OER electrocatalyst, and to improve its performance by modulating their intrinsic structure.

The preparation of alloy nanoparticles for hydrogen evolution reaction (HER) is a feasible strategy to optimize the inherent electronic structure of bimetallic catalysts, affording high catalytic activity. However, most of the metal alloys prepared currently exist in the form of bimetals, so it is urgent to find a facile method for preparing alloys. Herein, we developed a facile process by desulfurization from bimetallic sulfide solid solution for effectively constructing an electrocatalyst of RuNi alloy implanted with S-doped defective carbon (RuNi-alloy@SC), which performs outstanding HER performance in both acidic and alkaline solutions. As expected, the optimized catalyst displayed quite a low overpotential of 34 mV at current density of 10 mA cm−2, small Tafel slope of 55 mV dec−1, and long-term durability over 120 h for HER operation in acidic solution. In alkaline medium, the low overpotential and Tafel slope of 93 mV and 96 mV dec−1 were further achieved. Density functional theory (DFT) simulations reveal the hydrogen adsorption free energy (ΔGH*) of RuNi alloy with different crystal faces, in which RuNi (1 0 3) face enables the lowest ΔGH* for HER, whose value equals to that of the Pt. This work provides an advanced method and novel insights into the design of alloy electrocatalyst for HER.

The interfacial design and defect engineering are of huge interest for achieving efficient photocatalytic H2 evolution using solar energy. In this work, we successfully integrated the Schottky junction and S-scheme heterojunction with oxygen vacancies to achieve the defective Ru/SrTiO3/TiO2 hybrid photocatalyst. As verified by experimental studies, these junctions with defects fully exploit the benefits of interfacial charge separation and transport. It is demonstrated that the designed hybrid exhibits dramatically enhanced photocatalytic H2 evolution rate with respect to pristine SrTiO3, high apparent quantum efficiency at 365 nm irradiation as well as excellent stability. Furthermore, the Ru/SrTiO3/TiO2 based device photocatalyst also displays the excellent H2 evolution activity with easy recycle nature. This finding provides a newfangled thought for developing highly efficient hybrid materials for photocatalytic H2 evolution.

For a variety of electrocatalytic reactions, such as CO2 reduction, O2 reduction/precipitation, N2 reduction, etc., the activity, selectivity and stability of electrocatalysts play a vital role in energy efficiency and system performance. Atomically dispersed catalysts (ADCs) have attracted much attention due to their high catalytic activity and selectivity. However, the ultra-high surface free energy of single atoms makes the easily formation of clusters or/and nanoparticles. Therefore, it is still a huge challenge to develop universal methods to stabilize the high-density atomically dispersed catalysts (HADCs). This review highlights and summarizes the assembling principle and universal strategies for the preparation of HADCs, such as metal–organic frameworks (MOFs) deriving, template-assisting, defects-trapping, wet-chemistry and heteroatom anchoring routes. Meanwhile, the applications of HADCs in energy conversion are systematically summarized. Significantly, the key to achieving mass production of HADCs through economical and efficient synthesis are discussed. Finally, the current challenges and future prospects of HADCs for preparation strategy are discussed. We sincerely believe that this review will provide an ideal guide and inspiration to theoretical and experimental design and prepare the HADCs.

This paper reports a novel hybridization of heterogeneous atoms to regulate the photocatalytic behavior of graphitic carbon nitride (g-C3N4) by controlling its energy band structure. The K+-modified g-C3N4 (KCN) was obtained by KCl/LiCl molten-salt treating the urea-derived pristine g-C3N4 (CN), and the H+-modified g-C3N4 (HCN) was obtained by HCl-treating KCN. The photocatalytic hydrogen evolution reaction (HER) and gaseous acetaldehyde degradation (GAD) results show that KCN exhibits a high HER rate of 3447 μmol h−1 g−1, up to 19 times that of CN, whereas HCN has the GAD reaction rate constants of 0.876 and 4.352 h−1 under visible light and simulated solar light, respectively. The difference in photocatalytic HER and GAD resulted from the stronger reducibility of KCN and higher oxidizability of HCN, because of the efficient regulation in their energy band structures modified with K+ and H+.

This paper reported a facile microwave-assisted process to modify spent graphite (SG) powders for their re-utilization as LIBs anodes. The SG powders were treated by a simple impurity-removal process and a microwave irradiation in air for an exposure time range of 15–40 s. The as-obtained samples were characterized via various techniques. The microwave-modified samples (MW-G) exhibit enlarged interlayer distances and some open sites in their layers. The results show that the microwave-irradiation time has an obvious effect on their energy-storage property, and too long irradiation is harmful for their performance. The sample (MW-G-15) with a microwave-irradiation time of 15 s displays a high specific capacity of ≥ 400 mAh g–1, much higher than that (~300 mAh g–1) of the fresh commercially available graphite under the same test condition. MW-G-15 has a capacity retention of 96% and an initial coulombic efficiency (ICE) of 84%, and the charge transfer and rate capacities are highly improved. The enhanced performances of MW-G-15 are attributed to the reconstruction of graphite structure during the microwave irradiation by introducing suitable open sites or channels for the intercalation and migration of Li ions. This work gives a useful enlightenment to explore low-cost and eco-friendly approach towards re-utilization of spent graphite as LIBs anode materials.

To seek effective strategies that improve the photoelectrochemical water oxidation performance of hematite (α-Fe2O3) photoanodes is still challenging owning to their abundant surface states and low charge transfer efficiency. Herein, a facile impregnation method with an annealing process was developed to synthesize MoO3 modified Fe2O3 photoanodes using the MoO3 layer as an effective passivation component to decrease surface states and thus to improve the charge separation and transfer process at the electrode/electrolyte interfaces. The oxygen vacancies were subsequently introduced to steer the electrical conductivity, and further to boost the charge separation and transfer. The optimized MoO3-x/Fe2O3-x photoanode displays a photocurrent density of 2.6 mA cm–2 at 1.23 V versus the reversible hydrogen electrode under AM 1.5 G irradiation, 2.2 times that of the Fe2O3 (1.2 mA cm–2). The synergetic integration of passivation layer and oxygen vacancies on photoelectrodes heralds an efficient paradigm for solar energy conversion.

In the development of photocatalytic hydrogen (H2) production, designing and optimizing photocatalyst nanostructures with efficient charge transfer and separation for catalytically active sites are still a great challenge. Herein, a well-controlled synthetic strategy is developed to prepare an Mo2C/TiO2 hetero-nanostructure, in which the TiO2 3D hierarchical configuration is loaded with highly dispersed Mo2C nanoparticles. This heterostructure achieves the excellent photocatalytic activity of 39.4 mmol h−1 g−1 with its rate ∼25 times higher than that of pristine TiO2. Also, our photocatalysts process excellent long-term durability (>20 h). The impressive photocatalytic H2 activity of Mo2C/TiO2 indicates favourable charge carrier dynamics, as determined by the results of photoluminescence (PL), time-resolved photoluminescence (TRPL), surface photovoltage (SPV), and open circuit potential (OCP) decay curves. Moreover, this study provides a guide for researchers to design new functional materials with excellent hydrogen production activity.

A precursor-engineering strategy coupled with a microwave molten-salt process (PE-MWMS) is developed to synthesize graphitic carbon nitride (g-C

The Ewald3D sum with the tinfoil boundary condition (e3dtf) evaluates the electrostatic energy of a finite unit cell inside an infinitely periodic supercell. Although it has been used as a {\it de facto} standard treatment of electrostatics for simulations of extended polar or charged interfaces, the finite-size effect on simulated properties has yet to be fully understood. There is, however, an intuitive way to quantify the average effect arising from the difference between the e3dtf and Coulomb potentials on the response of mobile charges to contact surfaces with fixed charges and/or to an applied external electric field. While any charged interface formed by mobile countercharges that compensate the fixed charges slips upon the change of the acting electric field, the distance between a pair of oppositely charged interfaces is found to be nearly stationary, which allows an analytic finite-size correction to the amount of countercharges. Application of the theory to solvated electric double layers (insulator/electrolyte interfaces) predicts that the state of complete charge compensation is invariant with respect to solvent permittivities, which is confirmed by a proper analysis of simulation data in the literature., 8 pages, 5 figures

Hematite (α-Fe2O3) based nanomaterials are considered as the most promising photoelectrodes for solar water splitting. However, some inherent shortcomings like high density of surface states is still the critically challengeable issue. This paper reports the integration of In2O3 nanolayers (NLs) on the surface of worm-like Fe2O3 films to significantly improve the photoelectrochemical (PEC) water oxidation activity. The In2O3 NLs on the modified α-Fe2O3 photoelectrodes exhibit dual positive effects on PEC performance: i) acting as the passivation material to decrease surface electron-hole recombination losses; ii) constructing heterojunctions with Fe2O3 to facilitate efficient separation of surface charges and spatial transfer with extended lifetimes. The resulting treated Fe2O3 photoanode yields a current density of 3.4 mA cm―2 at 1.23 V vs. reversible hydrogen electrode and high incident photon-to-current efficiency of 80 % at 400 nm. These results may bring inspiration to introduce multifunctional modifiers on photoelectrodes that offer practically high-performance PEC applications.

Novel synthesis of efficient noble-metal-free electrocatalysts for both oxygen reduction/evolution reaction (ORR/OER) in energy conversion devices (e.g., fuel cells, metal–air batteries) is of essential significance for further sustainable development. This paper reports a facile synthesis of Fe–N–C species-modified carbon nanotubes (F/N-CNTs) for ORR application by directly pyrolyzing a fluffy hybrid precursor at a moderate temperature ([Formula: see text]C) in Ar. The fluffy hybrid precursors consisting of nitro-hydrochloric-acid-treated CNTs, melamine and Fe[Formula: see text] species are prepared via a freeze-drying method. On account of the synergistic effect of various active sites, including pyridine–N, Fe–Nx and Fe3C, and the high conductivity of the CNTs matrix, the as-obtained F/N-CNT electrocatalysts exhibit excellent ORR activities, comparable to commercial Pt/C. The addition of N heteroatoms, the dosage of Fe and the pyrolysis temperature highly influence the ORR properties of the F/N-CNT samples. The typical F/N-CNT sample obtained at the optimized parameters shows an onset potential of 1.06[Formula: see text]V and a half-wave potential of 0.91[Formula: see text]V versus reversible hydrogen electrode (RHE) in an alkaline condition, more positive than those (1.01[Formula: see text]V and 0.88[Formula: see text]V versus RHE) of Pt/C. The F/N-CNT exhibits outstanding bifunctional ORR/OER activity and excellent methanol tolerance, and the F/N-CNT-based Zn–air battery (ZAB) with an open-circuit voltage (OCV) of 1.405[Formula: see text]V presents a current density of 125[Formula: see text]mA[Formula: see text]cm[Formula: see text] and a power density of 76.5[Formula: see text]mW[Formula: see text]cm[Formula: see text]; these electrocatalytic properties are highly superior to Pt/C. The direct pyrolysis of fluffy hybrid precursors provides a concise but robust technical platform to achieve high-performance noble-metal-free electrocatalysts with ORR/OER activities superior to Pt/C.

Enzyme free glucose detection is widely concerned because of its high stability and low cost, however, the sensitivity is relatively low in neutral solution. Compared with electrochemical sensor, photoelectrochemical sensor is more sensitive due to the independent excitation and detection source. Here, we present a Cu/ZnO nano-thorn array for photoelectrochemical detection to glucose in neutral solution，in which the uniform array structure and the Cu nanorod inside provide excellent conductivity, and the outside ZnO nanowire branches ensure large electrochemical active area. Moreover, the Schottky junction formed between the trunk of Cu nanorod and the branches of ZnO nanowires facilitates the separation of photogenerated electrons and holes. Therefore, the Cu/ZnO nano-thorn exhibits good photoactivity, which also shows an excellent performance in photoelectrochemical detection of glucose in neutral solution with a sensitivity of 63.76 μA mM−1 cm−2 in the range of 0.1–4.5 mmol l−1, and a limit detection of 3.762 μmol l−1.

The combination of noble metal and transition metal oxide (TMO) can effectively expand their application in electrochemistry. However, rational design and convenient fabrication of the noble metal/TMO nanoarray is rarely reported. Here, Cu3Pt/Cu2O nanorod array was constructed on copper substrate by a convenient method and used as non-enzymatic glucose detector. In the nanorod, Moreover, the glycol ligand acted as a bridge for electron transfer from Cu2O at surface to Cu3Pt and the nanorod structure of Cu3Pt could serve as a highway for electron transfer, hence, when the Cu3Pt/Cu2O nanorod array was used as glucose detector, it delivered enhanced linear detection range (0.005–0.1 mM, 0.1–1.5 mM and 1.5–10 mM), high corresponding sensitivity (5082 μA mM−1 cm−2, 3331 μA mM−1 cm−2 and 118 μA mM−1 cm−2), fast response time (

Although biotechnologies for astaxanthin production from Haematococcus pluvialis have been developed for decades and many production facilities have been established throughout the world, the production cost is still high. This paper is to evaluate the current production processes and production facilities, to analyze the R&D strategies for process improvement, and to review the recent research advances shedding light on production cost reduction. With these efforts being made, we intent to conclude that the production cost of astaxanthin from Haematococcus might be substantially reduced to the levels comparable to that of chemical astaxanthin through further R&D and the future research might need to focus on strain selection and improvement, cultivation process optimization, innovation of cultivation methodologies, and revolution of extraction technologies.