Biophysical phenotyping of single-cell based on impedance and application for individualized precision medicine.

Single-cell biophysical characterization based on impedance measurement is an advantageous approach due to its label-free, high-efficiency, cost-effective and real-time capability. Biophysical phenotyping can yield timely and rich information on physiological and pathological state of cells for disease diagnosis, drug screening, precision medicine, etc. However, precise measurement on single-cell impedance is challenging, particularly hard to figure out the detailed biophysical parameters of single cell due to coupling and complexity of impedance model. Here, we propose an analytic determination method to decode single-cell electrophysiological parameters (including cell-substrate interface capacitance, cell membrane capacitance, cell membrane conductivity, and cytoplasm conductivity) from the impedances measured at optimized frequencies by using analytic solution rather than spectrum fitting. With this simple and fast analytic solution method, the physiological parameters of single cell in natural adhesion state can be accurately determined in real time. We validate this cell parameter determination method in monitoring the change of cell adhesion under hydraulic effects and exploring electrophysiological differences among MCF-7, HeLa, Huh7, and MDA-MB-231 cell lines. Particularly, we apply the approach to optimize tumor treating fields (TTFields) therapy, realizing individualized precision medicine. Our work provides an accurate and efficient approach for characterizing single-cell biophysical properties with real-time, in-situ, label-free, and less invasive advantages.

Unveiling activation mechanism of persulfate by homologous hemp-derived biochar catalysts for enhanced tetracycline wastewater remediation.

Advancements in biochar activating persulfate advanced oxidation processes (PS-AOP), have gained significant attention. However, the understanding of biochar-based catalysts in activating PS remains limited. Herein, biochar (BC) and N-doped biochar (NBC) were synthesized from hemp for activating PS to treat tetracycline (TC) wastewater and analyzed their mechanisms separately. Surprisingly, N-doped in biochar leads to a change in the activation mechanism of PS. The BC-PS system operates mainly through a radical pathway, advantageous for treating soil organic pollution (68%) with pH adaptability (less than 10% variation). Nevertheless, the NBC-PS system primarily employs an electron transfer non-radical pathway, demonstrating stability (only 7% performance degradation over four cycles) and enhanced resistance to anionic interference (less than 10% variation) in organic wastewater treatment. This study provides a technical reference and theoretical foundation for enhancing biochar activation of PS in the removal of organic pollutants from aquatic and terrestrial environments.

Complementary Weaknesses: A Win-Win Approach for rGO/CdS to Improve the Energy Conversion Performance of Integrated Photorechargeable Li-S Batteries.

Integrating solar energy into rechargeable battery systems represents a significant advancement towards sustainable energy storage solutions. Herein, we propose a win-win solution to reduce the shuttle effect of polysulfide and improve the photocorrosion stability of CdS, thereby enhancing the energy conversion efficiency of rGO/CdS-based photorechargeable integrated lithium-sulfur batteries (PRLSBs). Experimental results show that CdS can effectively anchor polysulfide under sunlight irradiation for 20 minutes. Under a high current density (1 C), the discharge-specific capacity of the PRLSBs increased to 971.30 mAh g-1, which is 113.3 % enhancement compared to that of under dark condition (857.49 mAh g-1). Remarkably, without an electrical power supply, the PRLSBs can maintain a 21 hours discharge process following merely 1.5 hours of light irradiation, achieving a breakthrough solar-to-electrical energy conversion efficiency of up to 5.04 %. Ex situ X-ray photoelectron spectroscopy (XPS) and in situ Raman analysis corroborate the effectiveness of this complementary weakness approach in bolstering redox kinetics and curtailing polysulfide dissolution in PRLSBs. This work showcases a feasible strategy to develop PRLSBs with potential dual-functional metal sulfide photoelectrodes, which will be of great interest in future-oriented off-grid photocell systems.

Unveiling the Synergistic Role of Frustrated Lewis Pairs in Carbon-Encapsulated Ni/NiOx Photothermal Cocatalyst for Enhanced Photocatalytic Hydrogen Production.

The development of high-density and closely spaced frustrated Lewis pairs (FLPs) is crucial for enhancing catalyst activity and accelerating reaction rates. However, constructing efficient FLPs by breaking classical Lewis bonds poses a significant challenge. Here, this work has made a pivotal discovery regarding the Jahn-Teller effect during the formation of grain boundaries in carbon-encapsulated Ni/NiOx (Ni/NiOx@C). This effect facilitates the formation of high-density O (VO) and Ni (VNi) vacancy sites with different charge polarities, specifically FLP-VO-C basic sites and FLP-VNi-C acidic sites. The synergistic interaction between FLP-VO-C and FLP-VNi-C sites not only reduces energy barriers for water adsorption and splitting, but also induces a strong photothermal effect. This mutually reinforcing effect contributes to the exceptional performance of Ni/NiOx@C as a cocatalyst in photothermal-assisted photocatalytic hydrogen production. Notably, the Ni/NiOx@C/g-C3N4 (NOCC) composite photocatalyst exhibits remarkable hydrogen production activity with a rate of 10.7 mmol g-1 h-1, surpassing that of the Pt cocatalyst by 1.76 times. Moreover, the NOCC achieves an impressive apparent quantum yield of 40.78% at a wavelength of 380 nm. This work paves the way for designing novel defect-state multiphase cocatalysts with high-density and adjacent FLP sites, which hold promise for enhancing various catalytic reactions.

Enhanced Photothermal Activity of Nanoconjugated System via Covalent Organic Frameworks as the Springboard.

The development of nanomaterials with high photothermal conversion efficiency has been a hot issue. In this work, a novel photothermal nanomaterial is synthesized using Prussian blue nanocubes (PBNCs) as the photothermal active substance and covalent organic framework (COF) as the substrate. The as-prepared COF@PBNCs show a high photothermal conversion efficiency of 59.1%, significantly higher than that of pure PBNCs (32.5%). A new circuit path is generated with the combination of COF, which prevents the direct combination of thermal electrons and holes, as well as enhances the nonradiation transition of PBNCs. Besides, the imine groups on COF as the coordination and reduction agent allow the in situ growth of PBNCs, and the dense micropores of COF as the ideal heat conduction channels can also be the potential factors for the enhanced photothermal property. The photothermal property of COF@PBNCs is further used in the construction of immunosensor for the detection of furosemide (FUR). With the help of handheld thermal imager, the concentration of FUR can be easily read, thus shedding a new light in the construction of visual sensor for simple and low-cost point-of-care testing.

Bifunctional Ni Foam Supported TiO2 @Ni3 S2 core@shell Nanorod Arrays for Boosting Electrocatalytic Biomass Upgrading and H2 Production Reactions.

Replacing traditional oxygen evoltion reaction (OER) with biomass oxidation reaction (BOR) is an advantageous alternative choice to obtain green hydrogen energy from electrocatalytic water splitting. Herein, a novel of extremely homogeneous Ni3 S2 nanosheets covered TiO2 nanorod arrays are in situ growth on conductive Ni foam (Ni/TiO2 @Ni3 S2 ). The Ni/TiO2 @Ni3 S2 electrode exhibits excellent electrocatalytic activity and long-term stability for both BOR and hydrogen evolution reaction (HER). Especially, taking glucose as a typical biomass, the average hydrogen production rate of the HER-glucose oxidation reaction (GOR) two-electrode system reached 984.74 µmol h-1 , about 2.7 times higher than that of in a common HER//OER two-electrode water splitting system (365.50 µmol h-1 ). The calculated power energy saving efficiency of the GOR//HER system is about 13% less than that of the OER//HER system. Meanwhile, the corresponding selectivity of the value-added formic acid produced by GOR reaches about 80%. Moreover, the Ni/TiO2 @Ni3 S2 electrode also exhibits excellent electrocatalytic activity on a diverse range of typical biomass intermediates, such as urea, sucrose, fructose, furfuryl alcohol (FFA), 5-hydroxymethylfurfural (HMF), and alcohol (EtOH). These results show that Ni/TiO2 @Ni3 S2 has great potential in electrocatalysis, especially in replacing OER reaction with BOR reaction and promoting the sustainable development of hydrogen production.

Synergistic Bimetallic CoCu-Codecorated Carbon Nanosheet Arrays as Integrated Bifunctional Cathodes for High-Performance Rechargeable/Flexible Zinc-Air Batteries.

The unremitting exploration of well-architectured and high-efficiency oxygen electrocatalysts is promising to speed up the surface-mediated oxygen reduction/evolution reaction (ORR/OER) kinetics of rechargeable zinc-air batteries (ZABs). Herein, bimetallic CoCu-codecorated carbon nanosheet arrays (CoCu/N-CNS) are proposed as self-supported bifunctional oxygen catalysts. The integrated catalysts are in situ constructed via a simple sacrificial-templated strategy, imparting CoCu/N-CNS with 3D interconnected conductive pathways, abundant mesopores for electrolyte penetration and ion diffusion, as well as Cu-synergized Co-Nx /O reactive sites for improved catalytic activities. By incorporating a moderate amount of Cu into CoCu/N-CNS, the bifunctional activities can be further increased due to synergistic oxygen electrocatalysis. Consequently, the optimized CoCu/N-CNS realizes a low overall overpotential of 0.64 V for OER and ORR and leads to high-performance liquid ZABs with high gravimetric energy (879.7 Wh kg-1 ), high peak power density (104.3 mW cm-2 ), and remarkable cyclic stability upon 400 h/1000 cycles at 10 mA cm-2 . More impressively, all-solid-state flexible ZABs assembled with the CoCu/N-CNS cathode exhibit superior rate performance and exceptional mechanical flexibility under arbitrary bending conditions. This CoCu/N-CNS monolith holds significant potential in advancing cation-modulated multimetallic electrocatalysts and multifunctional nanocatalysts.

Shape-specific MOF-derived Cu@Fe-NC with morphology-driven catalytic activity: Mimicking peroxidase for the fluorescent- colorimetric immunosignage of ochratoxin.

Ochratoxin A (OTA), which has strong hepatotoxicity and nephrotoxicity, can accumulate in the human body through the food chain; thus, the selective and effective detection of OTA is urgently required for food security. Nanozymes with hyperfine size and shape control have attracted attention because of their controllable structure and intrinsic activity. Herein, CuFe-bimetal coordinated N-doped carbon (Cu@Fe-NC) with morphology-driven peroxidase-mimicking activity was synthesized using Cu2O with specific polygonal cubes and fully exposed {111} crystalline facets as the template to produce a CuFe-bimetallic metal organic framework (MOF) and further treating CuFe-MOF with high-temperature pyrolysis. N-doping can confer electronegativity to exhibit high affinity, while the large surface area of the porous carbon support can facilitate rapid adsorption-desorption equilibrium. Using the peroxidase-mimicking Cu@Fe0.5-NC as a carrier, a versatile immunoassay for the detection of OTA was implemented based on the ratiometric fluorescence and the localized surface plasmon resonance peak shift, achieving a detection limit of 0.52 ng/L in the range of 0.001-10 µg/L. Therefore, the strategy of enhancing enzyme-mimicking activity using specific shapes and crystalline facets may open new avenues for food and environmental analysis.

Electroporation-Assisted Surface-Enhanced Raman Detection for Long-Term, Label-Free, and Noninvasive Molecular Profiling of Live Single Cells.

Molecule characterization of live single cells is greatly important in disease diagnoses and personalized treatments. Conventional molecule detection methods, such as mass spectrography, gene sequencing, or immunofluorescence, are usually destructive or labeled and unable to monitor the dynamic change of live cellular molecules. Herein, we propose an electroporation-assisted surface-enhanced Raman scattering (EP-SERS) method using a microchip to implement label-free, noninvasive, and continuous detections of the molecules of live single cells. The microchip containing microelectrodes with nanostructured EP-SERS probes has a multifunction of cell positioning, electroporation, and SERS detection. The EP-SERS method capably detects both the intracellular and extracellular molecules of live single cells without losing cell viability so as to enable long-term monitoring of the molecular pathological process in situ. We detect the molecules of single cells for two breast cancer cell lines with different malignancies (MCF-7 and MDA-MB-231), one liver cancer cell line (Huh-7), and one normal cell line (293T) using the EP-SERS method and classify these cell types to achieve high accuracies of 91.4-98.3% using their SERS spectra. Furthermore, 24 h continuous monitoring of the heterogeneous molecular responses of different cancer cell lines under doxorubicin treatment is successfully implemented using the EP-SERS method. This work provides a long-term, label-free, and biocompatible approach to simultaneously detect intracellular and extracellular molecules of live single cells on a chip, which would facilitate research and applications of cancer diagnoses and personalized treatments.

Computer-Vision-Based Dielectrophoresis Mobility Tracking for Characterization of Single-Cell Biophysical Properties.

Fast and precise measurements of live single-cell biophysical properties is significant in disease diagnosis, cytopathologic analysis, etc. Existing methods still suffer from unsatisfied measurement accuracy and low efficiency. We propose a computer vision method to track cell dielectrophoretic movements on a microchip, enabling efficient and accurate measurement of biophysical parameters of live single cells, including cell radius, cytoplasm conductivity, and cell-specific membrane capacitance, and in situ extraction of cell texture features. We propose a prediction-iteration method to optimize the cell parameter measurement, achieving high accuracy (less than 0.79% error) and high efficiency (less than 30 s). We further propose a hierarchical classifier based on a support vector machine and implement cell classification using acquired cell physical parameters and texture features, achieving high classification accuracies for identifying cell lines from different tissues, tumor and normal cells, different tumor cells, different leukemia cells, and tumor cells with different malignancies. The method is label-free and biocompatible, allowing further live cell studies on a chip, e.g., cell therapy, cell differentiation, etc.

Electrospun nanofibrous membrane with antibacterial and antiviral properties decorated with Myoporum bontioides extract and silver-doped carbon nitride nanoparticles for medical masks application.

Public health safety issues have been plaguing the world since the pandemic outbreak of coronavirus disease (COVID-19). However, most personal protective equipments (PPE) do not have antibacterial and anti- toxicity effects. In this work, we designed and prepared a reusable, antibacterial and anti-toxicity Polyacrylonitrile (PAN) based nanofibrous membrane cooperated with Ag/g-C3N4 (Ag-CN), Myoporum.bontioides (M. bontioides) plant extracts and Ag nanoparticles (NPs) by an electrospinning-process. The SEM and TEM characterization revealed the formation of raised, creased or wrinkled areas on the fiber surface caused by the Ag nanoparticles, the rough surface prevented the aerosol particles on the fiber surface from sliding and stagnating, thus providing excellent filtration performance. The PAN/M. bontioides/Ag-CN/Ag nanofibrous membrane could be employed as a photocatalytic bactericidal material, which not only degraded 96.37% of methylene blue within 150 min, but also exhibited the superior bactericidal effect of 98.65 ± 1.49% and 97.8 ± 1.27% against E. coli and S. aureus, respectively, under 3 hs of light exposure. After 3 cycles of sterilization experiments, the PAN/M. bontioides/Ag-CN/Ag nanofibrous membrane maintained an efficient sterilization effect. Molecular docking revealed that the compounds in M. bontioides extracts interacted with neo-coronavirus targets mainly on Mpro and RdRp proteins, and these compounds had the strongest docking energy with Mpro protein, the shortest docking radius, and more binding sites for key amino acids around the viral protein targets, which influenced the replication and transcription process of neo-coronavirus. The PAN/M.bontioides/Ag-CN/Ag nanofibrous membrane also performed significant inhibition of influenza A virus H3N2. The novel nanofiber membrane is expected to be applied to medical masks, which will improve human isolation and protection against viruses.

Efficient purification of tetracycline wastewater by activated persulfate with heterogeneous Co-V bimetallic oxides.

The persistence and wide dispersion of antibiotics have a severe impact on the ecological environment. Developing an effective method with universal applicability to remove pollutants is pretty necessary. Herein, a bimetallic oxides (Co3V2O8) heterogeneous material was successfully prepared and used to activate the persulfate (PS) for purification of tetracycline (TC) wastewater. By exploring the reaction conditions and influencing factors, the removal rate of 50 mg⋅L-1 TC reached 87.1% by Co3V2O8/PS system, and the reaction rate constant was up to 0.0271 min-1. As a highly efficient catalyst for the activation of PS, Co3V2O8/PS system produces radicals of SO4•-, •OH, •O2- and 1O2 in the reaction process due to the Co(II) and V(IV) exchange electrons with S2O82- and O2. Simultaneously, the internal electron exchange occurs between Co(II)/Co(III) and V(IV)/V(V), which stabilizes the content of Co(II) and V(IV). This work provides a novel activator for PS activation to degrade contaminants and contributes to a better understanding of the PS activation mechanism by transition compound.

AC/DC Electric-Field-Assisted Growth of ZnO Nanowires for Gas Discharge.

Using ZnO nanowires as needle anodes in gas discharge is helpful for maintaining continuous discharge with a relatively low voltage. It is necessary that the ZnO nanowires are far enough apart to guarantee no electric field weakening and that the nanowire anodes are easy to assemble together with the discharging devices. An AC/DC electric-field-assisted wet chemical method is proposed in this paper. It was used to grow ZnO nanowires directly on discharging devices. The nanowires covered the whole electrode in the case in which only a DC field was applied. Moreover, the tips of the nanowires were scattered, similar to the results observed under the application of AC fields. The average distance between the tips of the highest nanowires was approximately equal to 4 µm, which almost meets the requirement of gas discharge. The research concerning growing ZnO nanowires directly on PCBs shown that, at the current time, ZnO nanowires on PCBs did not meet the requirements of gas discharge; however, in this study, the parameters regarding ZnO nanowire growth were established.

Phase-Controllable Growth Nix Py Modified CdS@Ni3 S2 Electrodes for Efficient Electrocatalytic and Enhanced Photoassisted Electrocatalytic Overall Water Splitting.

The rational design and construction of cost-effective nickel-based phosphide or sulfide (photo)electrocatalysts for hydrogen production from water splitting has sparked a huge investigation surge in recent years. Whereas, nickel phosphides (Nix Py ) possess more than ten stoichiometric compositions with different crystalline. Constructing Nix Py with well crystalline and revealing their intrinsic catalytic mechanism at atomic/molecular levels remains a great challenge. Herein, an easy-to-follow phase-controllable phosphating strategy is first proposed to prepare well crystalline Nix Py (Ni3 P and Ni12 P5 ) modified CdS@Ni3 S2 heterojunction electrocatalysts. It is found that Ni3 P modified CdS@Ni3 S2 (CdS@Ni3 S2 /Ni3 P) exhibits remarkable stability and bifunctional electrocatalytic activities in both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). Density functional theory results suggest that P-Ni sites and P sites in CdS@Ni3 S2 /Ni3 P, respectively, serve as OER and HER active sites during electrocatalytic water splitting processes. Moreover, benefiting from the advantageous photocatalyst@electrocatalyst core@shell structure, CdS@Ni3 S2 /Ni3 P delivers an advantaged photoassisted electrocatalytic water splitting property. The champion electrical to hydrogen and solar to hydrogen energy conversion efficiencies of CdS@Ni3 S2 /Ni3 P, respectively, reach 93.35% and 4.65%. This work will provide a general guidance for synergistically using solar energy and electric energy for large-scale H2 production from water splitting.

A CuNi Alloy-Carbon Layer Core-Shell Catalyst for Highly Efficient Conversion of Aqueous Formaldehyde to Hydrogen at Room Temperature.

A copper (Cu) material is catalytically active for formaldehyde (HCHO) dehydrogenation to produce H2, but the unsatisfactory efficiency and easy corrosion hinder its practical application. Alloying with other metals and coating a carbon layer outside are recognized as effective strategies to improve the catalytic activity and the long-term durability of nonprecious metal catalysts. Here, highly dispersed CuNi alloy-carbon layer core-shell nanoparticles (CuNi@C) have been developed as a robust catalyst for efficient H2 generation from HCHO aqueous solution at room temperature. Under the optimized reaction conditions, the CuNi@C catalyst exhibits a H2 evolution rate of 110.98 mmol·h-1·g-1, which is 1.5 and 4.9 times higher than those of Cu@C and Ni@C, respectively, which ranks top among the reported nonprecious metal catalysts for catalytic HCHO reforming at room temperature to date. Furthermore, CuNi@C also displays excellent stability toward the catalytic HCHO reforming into H2 in tap water owing to the well-constructed carbon sheath protecting CuNi nanocrystals from oxidation in an alkaline medium. Combined with density functional theory calculations, the superior catalytic efficiency of CuNi@C for H2 generation results from the synergistic contribution between the massive active species from HCHO decomposition on the Cu sites and the remarkable H2 evolution activity on Ni sites. The improved performance of CuNi@C highlights the enormous potential of advancing noble-metal-free nanoalloys as cost-effective and recyclable catalysts for energy recovery from industrial HCHO wastewater.

Measurement of Electric Double Layer Capacitance Using Dielectrophoresis-Based Particle Manipulation.

An electric double layer (EDL) generally exists at the interface between a conductive electrode and its adjacent liquid electrolyte. Accurate measurement of the capacitance of EDL is requisite but a great challenge due to the complexity of its variation mechanism correlated with the magnitude and frequency of applied signals and the difficulty in measuring the inner layer potentials across the EDL. Herein, a novel dielectrophoresis (DEP)-based approach is proposed to measure the capacitance of an EDL at a microelectrode/electrolyte interface. The measurement is achieved by employing DEP manipulation to micro polystyrene (PS) spheres suspended in a liquid electrolyte and determining the capacitance of EDL on the microelectrodes from the moving velocities of spheres. This method allows measurement of the capacitances of EDL under alternating current (AC) signals with different magnitudes and frequencies, so that the capacitance change with the magnitude and frequency of the applied signal can be characterized. The method avoids the impedance interference from the liquid electrolyte, external measuring systems, and other crosstalks, enabling an accurate measurement of double layer capacitance. In addition, the inner layer potentials across EDL under different magnitudes and frequencies of applied signals are comprehensively investigated, which facilitates an understanding of the ion behavior at the interfacial boundary that governs external observations of electrochemical reactions. The accurate measurement of the capacitance of EDL is of significance to explore the mechanism of interfacial functioning of electrochemical and bioelectrical devices and systems.

Comparative transcriptomic and metabolomic analyses of carotenoid biosynthesis reveal the basis of white petal color in Brassica napus.

MAIN CONCLUSION: The molecular mechanism underlying white petal color in Brassica napus was revealed by transcriptomic and metabolomic analyses. Rapeseed (Brassica napus L.) is one of the most important oilseed crops worldwide, but the mechanisms underlying flower color in this crop are known less. Here, we performed metabolomic and transcriptomic analyses of the yellow-flowered rapeseed cultivar 'Zhongshuang 11' (ZS11) and the white-flowered inbred line 'White Petal' (WP). The total carotenoid contents were 1.778-fold and 1.969-fold higher in ZS11 vs. WP petals at stages S2 and S4, respectively. Our findings suggest that white petal color in WP flowers is primarily due to decreased lutein and zeaxanthin contents. Transcriptome analysis revealed 10,116 differentially expressed genes with a fourfold or greater change in expression (P-value less than 0.001) in WP vs. ZS11 petals, including 1,209 genes that were differentially expressed at four different stages and 20 genes in the carotenoid metabolism pathway. BnNCED4b, encoding a protein involved in carotenoid degradation, was expressed at abnormally high levels in WP petals, suggesting it might play a key role in white petal formation. The results of qRT-PCR were consistent with the transcriptome data. The results of this study provide important insights into the molecular mechanisms of the carotenoid metabolic pathway in rapeseed petals, and the candidate genes identified in this study provide a resource for the creation of new B. napus germplasms with different petal colors.

Genome-wide identification and expression profiling of the carotenoid cleavage dioxygenase (CCD) gene family in Brassica napus L.

Carotenoid cleavage dioxygenase (CCD), a key enzyme in carotenoid metabolism, cleaves carotenoids to form apo-carotenoids, which play a major role in plant growth and stress responses. CCD genes had not previously been systematically characterized in Brassica napus (rapeseed), an important oil crop worldwide. In this study, we identified 30 BnCCD genes and classified them into nine subgroups based on a phylogenetic analysis. We identified the chromosomal locations, gene structures, and cis-promoter elements of each of these genes and performed a selection pressure analysis to identify residues under selection. Furthermore, we determined the subcellular localization, physicochemical properties, and conserved protein motifs of the encoded proteins. All the CCD proteins contained a retinal pigment epithelial membrane protein (RPE65) domain. qRT-PCR analysis of expression of 20 representative BnCCD genes in 16 tissues of the B. napus cultivar Zhong Shuang 11 ('ZS11') revealed that members of the BnCCD gene family possess a broad range of expression patterns. This work lays the foundation for functional studies of the BnCCD gene family.

In Situ Photodeposited Construction of Pt-CdS/g-C3N4-MnOx Composite Photocatalyst for Efficient Visible-Light-Driven Overall Water Splitting.

For converting the renewable solar energy to hydrogen (H2) energy by photocatalytic (PC) overall water splitting (OWS), visible-light-driven photocatalysts are especially desired. Herein, a model CdS/g-C3N4 photocatalyst with a type II heterojunction is first demonstrated via a facile coupling of g-C3N4 nanosheets and CdS nanorods. After being combined with in situ photodeposited 3 wt % Pt and 4 wt % MnOx dual cocatalysts simultaneously, the optimal visible-light-driven (λ > 400 nm) composite photocatalyst of Pt-CdS/g-C3N4-MnOx gives a H2 generation rate of 9.244 µmol h-1 (924.4 µmol h-1 g-1) and a O2 evolution rate of 4.6 µmol h-1 (460 µmol h-1 g-1) in pure water, which is over 420 times higher than that of pure CdS nanorods loaded with 0.5 wt % Pt. The apparent quantum efficiency (AQE) reaches about 3.389% (at 400 nm) and 1.745% (at 420 nm), respectively. The combination of a type II heterojunction and simultaneous in situ photodeposition of the dual cocatalysts results in a dramatically improved PC efficiency and a long-term stability of the CdS/g-C3N4 visible-light-driven photocatalyst for OWS.

Strong adsorption of tetracycline hydrochloride on magnetic carbon-coated cobalt oxide nanoparticles.

The overuse of antibiotics, including tetracycline hydrochloride (TC), seriously threatens human health and ecosystems. In this work, magnetic carbon-coated cobalt oxide nanoparticles (CoO@C) were prepared by one-step annealing method and used as an adsorbent for efficient removal of TC from aqueous solution. The characteristic of the materials was studied by SEM, TEM, and XRD, revealing CoO nanoparticles (≤10 nm) were coated by carbon layer. Several influencial parameters, such as annealing temperature and pH on adsorption of TC, were explored, and found that the maximum adsorption capacity of CoO@C on TC reached as high as 769.43 mg g-1. Furthermore, CoO@C displayed excellent stability and reusability. After four repeated use of the adsorbent, the adsorption capacity still remained at 90% of the initial capacity. The pseudo-second order model and Temkin model proved that it was an exothermic chemical adsorption process. Furthermore, after analysis of FT-IR, Zeta-potential, XPS, the positive charge on the surface of CoO@C forms a strong electrostatic interaction with TC, and in addition, a surface bond is formed between the adsorbent and the TC molecule. This work provides a novel and efficient adsorbent for the purification of TC-containing wastewater.