Single-cell RNA sequencing identify SDCBP in ACE2-positive bronchial epithelial cells negatively correlates with COVID-19 severity.

The coronavirus disease 2019 (COVID-19), caused by the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has resulted in many deaths throughout the world. It is vital to identify the novel prognostic biomarkers and therapeutic targets to assist with the subsequent diagnosis and treatment plan to mitigate the expansion of COVID-19. Since angiotensin-converting enzyme 2 (ACE2)-positive cells are hosts for COVID-19, we focussed on this cell type to explore the underlying mechanisms of COVID-19. In this study, we identified that ACE2-positive cells from the bronchoalveolar lavage fluid (BALF) of patients with COVID-19 belong to bronchial epithelial cells. Comparing with patients of COVID-19 showing severe symptoms, the antigen processing and presentation pathway was increased and 12 typical genes, HLA-DRB5, HLA-DRB1, CD74, HLA-DRA, HLA-DPA1, HLA-DQA1, HSP90AA1, HSP90AB1, HLA-DPB1, HLA-DQB1, HLA-DQA2, and HLA-DMA, particularly HLA-DPB1, were obviously up-regulated in ACE2-positive bronchial epithelial cells of patients with mild disease. We further discovered SDCBP was positively correlated with above 12 genes particularly with HLA-DPB1 in ACE2-positive bronchial epithelial cells of COVID-19 patients. Moreover, SDCBP may increase the immune infiltration of B cells, CD8+ T cells, CD4+ T cells, macrophages, neutrophils and dendritic cells in different lung carcinoma. Moreover, we found the expression of SDCBP was positively correlated with the expression of antigen processing and presentation genes in post-mortem lung biopsies tissues, which is consistent with previous discoveries. These results suggest that SDCBP has good potential to be further developed as a novel diagnostic and therapeutic target in the treatment of COVID-19.

Achieving High-Quality Freshwater from a Self-Sustainable Integrated Solar Redox-Flow Desalination Device.

Solar-assisted electrochemical desalination has offered a new energy-water nexus technology for sustainable development in recent studies. However, only a few reports have demonstrated insufficient photocurrent, a low salt removal rate, and poor stability. In this study, a high-quality freshwater level of 5-10 ppm (from an initial feed of 10 000 ppm), an enhanced salt removal rate (217.8 µg cm-2 min-1 of NaCl), and improved cycling and long-term stability are achieved by integrating dye-sensitized solar cells (DSSCs) and redox-flow desalination (RFD) under light irradiation without additional electrical energy consumption. The DSSC redox electrolyte (I- /I3- ) is circulated between the photoanode (N719/TiO2 ) and intermediate electrode (graphite paper). Two DSSCs in parallel or series connections are directly coupled to the RFD device. Overall, this hybrid system can be used to boost photo electrochemical desalination technology. The energy-water nexus technology will open a new route for dual-role devices with photodesalination functions without energy consumption and solar-to-electricity generation.

miR-340 affects sauchinone inhibition of Th17 cell differentiation and promotes intestinal inflammation in inflammatory bowel disease.

The pathogenesis of inflammation bowel disease (IBD) involves exaggerated effector T cell responses and impaired regulatory T cell functions. We previously found that sauchinone (SAU) ameliorated experimental colitis via facilitating Th17 cell production of IL-10, but how SAU regulated Th17 cell differentiation remains unknown. MicroRNAs (miR) have been recognized as a crucial regulator of T cell biology and play a considerable role in IBD. Here, we demonstrated that SAU significantly suppressed miR-340 expression in Th17 cells, and enforced miR-340 expression abrogated SAU inhibition of Th17 differentiation. miR-340 itself was found to facilitate Th17 differentiation, especially the pathogenic "Th1-like" subset. In human IBD, miR-340 was intimately correlated with the disease severity. SAU markedly decreased miR-340 in the inflamed mucosa tissues from IBD patients. Scaffold/matrix-associated region-binding protein 1 (SMAR1) was identified as a target gene of miR-340. We revealed that blockade of miR-340 significantly reduced mucosal damage and Th17 responses in the lamina propria in a mouse colitis model. Our findings suggest that miR-340 negatively affects SAU inhibition of Th17 differentiation and might play a crucial role in the regulation of pathogenic "Th1-like" Th17 cell generation, which might serve as a novel therapeutic target of IBD.

MicroRNA-425 facilitates pathogenic Th17 cell differentiation by targeting forkhead box O1 (Foxo1) and is associated with inflammatory bowel disease.

Inflammatory bowel disease (IBD) is a chronic autoimmune disease, and its pathogenesis remains mostly unknown. MicroRNAs (miRs) has drawn much attention as a crucial regulator of autoimmune diseases. In this study, we demonstrated, for the first time, that miR-425 was significantly up-regulated in peripheral blood mononuclear cells (PBMC) and mucosa of patients with IBD. In note, T helper (Th) 17 cells were found to be the major source of miR-425 expression. Using gain-of-function approaches, we demonstrated that miR-425 could facilitate the differentiation of CD4+ T cells into Th17 lineage. In addition, forkhead box O1 (Foxo1) was identified as a novel target gene of miR-425, which was able to inhibit Th17 cell differentiation, and it was observed to be markedly decreased in PBMC and mucosa of patients with IBD. Notably, in vivo inhibition of miR-425 significantly alleviated the disease severity of TNBS-induced colitis in mice, with down-regulated levels of IL-17A. Our data reveal a novel mechanism in which the elevated miR-425 in IBD mediates pathogenic Th17 cell generation through down-regulation of Foxo1. In vivo blockade of miR-425 may serve as a novel therapeutic approach in the treatment of IBD.

MicroRNA-448 promotes multiple sclerosis development through induction of Th17 response through targeting protein tyrosine phosphatase non-receptor type 2 (PTPN2).

Multiple sclerosis (MS) is an immune-mediated demyelinating disease of the central nervous system, and its pathogenesis remains largely unclear. Much attention has been paid to the role of microRNAs (miRs) in regulation of autoimmune disease. Here, we found, for the first time, that miR-448 expression was significantly increased in periphery blood mononuclear cells (PBMC) and cerebrospinal fluid (CSF) of patients with MS, and its expression positively correlated with the disease severity. We further demonstrated that CD4+ T cells, especially the Th17 lineage, were the major source of miR-448 expression. Using gain- and loss-of-function approaches, we further verified that miR-448 could enhance Th17 differentiation, characterized by up-regulated expression levels of IL-17A and RORγt. Interleukin (IL)-1ß as a potent driver of pathogenic Th17 cells was able to strongly induce miR-448 expression in CD4+ T cells through activating NF-κB pathway. Additionally, we identified that miR-448 directly targeted protein tyrosine phosphatase non-receptor type 2 (PTPN2), which has been known as an anti-inflammatory player with capacity to suppress Th17 differentiation. We also observed markedly decreased expression of PTPN2 in PBMC and CSF of MS patients. Our results suggest that miR-448 might promote Th17 differentiation in MS and thus aggravate the disease through inhibiting PTPN2.

Preparation and photocatalytic properties of porous C and N co-doped TiO2 deposited on brick by a fast, one-step microwave irradiation method.

A one-step microwave irradiation method was used to deposit carbon and nitrogen co-doped TiO2 ((C, N)-TiO2) on commercial brick ((C, N)-TiO2/brick). The as-prepared samples were characterized by X-ray diffraction, ultraviolet-visible (UV-vis) diffuse reflectance spectroscopy, photoluminescence spectroscopy, X-ray photoelectron spectroscopy, and scanning electron microscopy (SEM). A selective technique was also used to investigate the concentration of hydroxyl radicals during UV-vis irradiation of the Methyl Orange solution with the as-prepared samples. The C and N dopants enhanced visible light absorption and provided a longer lifetime for the photo-generated electron-hole pairs. The SEM images showed that the as-prepared sample is porous. The dark adsorption and photodegradation test for (C, N)-TiO2/brick showed good photodegradation and good recyclability. The best photodegradation rate was 94% after 2hr. The maximum degradation rate was maintained even after the 6th cycle. The good photocatalytic properties are attributed to the enhanced visible light absorption, enhanced pollutant adsorption arising from the porous structure of the (C, N)-TiO2 thin film, and longer lifetime of the photo-generated electron-hole pairs. (C, N)-TiO2/brick should have potential commercial applications in photodegradation processes because of its low cost, good photodegradation, and excellent recyclability.

Design and simple synthesis of composite Bi12TiO20/Bi4Ti3O12 with a good photocatalytic quantum efficiency and high production of photo-generated hydroxyl radicals.

Hybrid Bi12TiO20/Bi4Ti3O12 composites with different Bi : Ti molar ratios were successfully fabricated using a one-step solid-state calcination. These samples were characterized using X-ray diffraction, specific surface area analysis, scanning electron microscopy, high-resolution microscopy, selected-area electron diffraction, X-ray photoelectron spectroscopy, UV-vis diffuse reflection spectroscopy, photoluminescence analyses, and photocurrent and electrochemical impedance spectroscopy. Some specified techniques were also used to investigate the photocatalytic properties and the formation of radical species under UV-vis irradiation. The composites provide an efficient pathway for photo-produced electrons and holes to diffuse and transfer to the exterior of the particles for photodegradation, because of the good contact between hybrid Bi12TiO20 and Bi4Ti3O12. Therefore, the hybrid Bi12TiO20/Bi4Ti3O12 can prolong the carrier lifetime as compared to any individual material (Bi12TiO20 or Bi4Ti3O12). In particular, the hybrid Bi12TiO20/Bi4Ti3O12 composite with a Bi : Ti ratio of 12 : 6 had the longest photo-generated carrier lifetime and produced the maximum amount of hydroxyl radicals during UV-vis irradiation; therefore, it demonstrated the best photo-catalytic properties. A Z-scheme mechanism was proposed to explain the hydroxyl radical yield and photodegradation.

Early outcomes of single-site versus multi-port robotic-assisted radical prostatectomy: A systematic review and meta-analysis.

BACKGROUND: Single-site robotic-assisted radical prostatectomy (ssRARP) has been promoted in many institutions due to its minimally invasive approach. This review aimed to investigate early outcomes of ssRARP in comparison with multi-port robotic-assisted radical prostatectomy (mpRARP). METHODS: A systematic literature search was performed for articles related to ssRARP case series and studies that compared ssRARP with mpRARP. The primary outcomes were functional and oncological outcomes, incision length, length of hospital stay and cost. RESULTS: 24 ssRARP case series involving 1385 cases, and 11 comparative studies involving 573 ssRARP cases and 980 mpRARP cases were included. Rate of immediate, 3-month, 6-month and 12-month recovery of continence in the ssRARP case series were 41 % [95 % CI: 0.38-0.45], 70 % [95 % CI: 0.67-0.73], 90 % [95 % CI: 0.87-0.93] and 93 % [95 % CI: 0.90-0.96]. 3-month potency recovery and positive surgical margin rate were 53 % [95 % CI: 0.46-0.60] and 21 % [95 % CI: 0.19-0.24]. No significant differences were detected between ssRARP and mpRARP in terms of 3-month (OR: 1.12; 95 % CI: 0.80-1.57) or 6-month (OR: 0.72; 95 % CI: 0.36-1.46) continence recovery rate, 3-month potency recovery rate (OR: 0.92; 95 % CI: 0.50-1.70), positive surgical margin rate (OR: 0.83; 95 % CI: 0.62-1.11), biochemical recurrence rate or total cost. Furthermore, ssRARP was associated with a significantly shorter length of incision and hospital stay. CONCLUSION: ssRARP has significant advantages in cosmetic effect, length of incision and rapid recovery. Consequently, ssRARP is expected to become the preferred form although more evidence is needed to determine its long-term effect.

Ezetimibe inhibits the migration and invasion of triple-negative breast cancer cells by targeting TGFß2 and EMT.

The important role of cholesterol in tumor metastasis has been widely studied in recent years. Ezetimibe is currently the only selective cholesterol uptake inhibitor on the market. Here, we explored the effect of ezetimibe on breast cancer metastasis by studying its impact on breast cancer cell migration, invasion, and epithelial-mesenchymal transition (EMT). Differential gene expression analysis and validation were also carried out to compare ezetimibe-treated and untreated breast cancer cells. Finally, breast cancer cells overexpressing TGFß2 were constructed, and the effect of TGFß2 on the migration and invasion of ezetimibe-treated breast cancer cells was examined. Our results show that ezetimibe treatment of breast cancer cells inhibited cell migration, invasion, and EMT, and it significantly suppressed the expression of TGFß2. Overexpression of TGFß2 reversed the inhibitory effect of ezetimibe on the migration and invasion of breast cancer cells. Taken together, our results suggest that ezetimibe might be a potential candidate for the treatment of breast cancer metastasis.

In-situ Preparation of Iron(II)-phthalocyanine@multi-walled-CNTs Nanocomposite for Quasi-solid-state Flexible Symmetric Supercapacitors with Long Cycling Life.

The construction of supercapacitor electrode materials with exceptional performance is the crucial to the commercialisation of flexible supercapacitors. Here, a novel in-situ precipitation technique was applied for constructing iron(II)-phthalocyanine (FePc) based nanocomposite as the electrode material in quasi-solid-state flexible supercapacitors. The highly redox-active FePc nanostructures were grown in the multi-walled-CNTs (MWCNTs) networks, which shows convenient electron/electrolyte ion transport pathways along with outstanding structural stability, leading to high energy storage and long cycling life. The electrode of FePc@MWCNTs delivered a higher specific capacity than that of individual MWCNTs and FePc. The quasi-solid-state symmetric flexible device that was constructed using FePc@MWCNTs electrode demonstrated impressive performance with a maximum energy density of 29.7 Wh kg-1 and a maximum power density of 4000 W kg-1. Moreover, the device demonstrated superior durability and flexibility, as evidenced by its exceptional cyclic stability (111.3%) even after 30000 cycles at 8 A g-1. These results reveal that the FePc@MWCNTs nanocomposite prepared by this simple in-situ precipitation method is promising as electrode material for next-generation flexible wearable power sources.

CuET overcomes regorafenib resistance by inhibiting epithelial-mesenchymal transition through suppression of the ERK pathway in hepatocellular carcinoma.

BACKGROUND AND PURPOSE: Regorafenib was approved by the US Food and Drug Administration (FDA) for hepatocellular carcinoma (HCC) patients showing progress on sorafenib treatment. However, there is an inevitably high rate of drug resistance associated with regorafenib, which reduces its effectiveness in clinical treatment. Thus, there is an urgent need to find a potential way to solve the problem of regorafenib resistance. The metabolite of disulfiram complexed with copper, the Diethyldithiocarbamate-copper complex (CuET), has been found to be an effective anticancer drug candidate. In the present study, we aimed to evaluate the effect of CuET on regorafenib resistance in HCC and uncover the associated mechanism. EXPERIMENTAL APPROACH: Regorafenib-resistant HCC strains were constructed by applying an increasing concentration gradient. This study employed a comprehensive range of methodologies, including the cell counting kit-8 (CCK-8) assay, colony formation assay, cell cycle analysis, wound healing assay, Transwell assay, tumor xenograft model, and immunohistochemical analysis. These methods were utilized to investigate the antitumor activity of CuET, assess the combined effect of regorafenib and CuET, and elucidate the molecular mechanism underlying CuET-mediated regorafenib resistance. KEY RESULTS: The inhibitory effect of regorafenib on cell survival, proliferation and migration was decreased in regorafenib-resistant MHCC-97H (MHCC-97H/REGO) cells compared with parental cells. CuET demonstrated significant inhibitory effects on cell survival, proliferation, and migration of various HCC cell lines. CuET restored the sensitivity of MHCC-97H/REGO HCC cells to regorafenib in vitro and in vivo. Mechanistically, CuET reverses regorafenib resistance in HCC by suppressing epithelial-mesenchymal transition (EMT) through inhibition of the ERK signaling pathway. CONCLUSION AND IMPLICATIONS: Taken together, the results of this study demonstrated that CuET inhibited the activation of the ERK signaling pathway, leading to the suppression of the epithelial-mesenchymal transition (EMT) and subsequently reversing regorafenib resistance in HCC both in vivo and in vitro. This study provides a new idea and potential strategy to improve the treatment of regorafenib-resistant HCC.

Improved reduction efficiency, cycling performance, and removal rate of hexavalent chromium by adding water-soluble salts.

Recently, the reaction speed and cycle performance of hexavalent chromium reduction over microsized zero-valent iron (ZVI) with an Fe0 core and iron oxide (FeOx) shell structure have been improved by activating the Fe0-core electrons through electromagnetic coupling between Fe0-core electrons and charges (hexavalent chromium in solution, double-charge layers of the ZVI/solution interface). Herein, the abovementioned electromagnetic coupling was greatly increased by adding salt (CH3COONa, NaCl, NaNO3, and Na2SO4) in the hexavalent chromium solution to increase the charge response. Adding salt greatly improved the reaction speed and cycle performance of hexavalent chromium reduction. It took 8 min to reduce hexavalent chromium with CH3COONa to below the discharge standard of wastewater in the first cycle and 20 min after reducing for 20 cycles. The best apparent rate of constant value (0.416 (min)-1) is nearly four times larger than those without salts. X-ray diffraction and X-ray photoelectron spectroscopy revealed the production of amorphous iron oxide shell with salt. The salt improves the hexavalent chromium reduction speed and cycle performance and impedes the Fe0-core-electron transfer via the produced Fe2O3, resulting in existence of an optimized salt dosage. This work aims to provide an effective route for enhancing the removal efficiency and cycle performance of heavy-metal-ion reduction via Fe0. And this work also proposes a novel viewpoint that adding salt in waste water would increase the electromagnetic coupling between the charges in solution and Fe0-core electrons which could finally activate the redox reaction.

Hypoxia signaling in cancer: Implications for therapeutic interventions.

Hypoxia is a persistent physiological feature of many different solid tumors and a key driver of malignancy, and in recent years, it has been recognized as an important target for cancer therapy. Hypoxia occurs in the majority of solid tumors due to a poor vascular oxygen supply that is not sufficient to meet the needs of rapidly proliferating cancer cells. A hypoxic tumor microenvironment (TME) can reduce the effectiveness of other tumor therapies, such as radiotherapy, chemotherapy, and immunotherapy. In this review, we discuss the critical role of hypoxia in tumor development, including tumor metabolism, tumor immunity, and tumor angiogenesis. The treatment methods for hypoxic TME are summarized, including hypoxia-targeted therapy and improving oxygenation by alleviating tumor hypoxia itself. Hyperoxia therapy can be used to improve tissue oxygen partial pressure and relieve tumor hypoxia. We focus on the underlying mechanisms of hyperoxia and their impact on current cancer therapies and discuss the prospects of hyperoxia therapy in cancer treatment.

Literature review, report, and analysis of genotype and clinical phenotype of a rare case of ulnar-mammary syndrome.

Objective: The clinical characteristics of Ulnar-mammary syndrome (UMS) caused by mutations in TBX3 (T-Box transcription factor 3) were studied and the correlation between genotype and clinical phenotype were analyzed to improve awareness and early diagnosis of the disease. Methods: The clinical data of a boy aged 13 years and 5 months with left forearm deformity and growth retardation as the main features were analyzed. Genomic exon detection was performed, and the results were verified by Sanger sequencing. Simultaneously, we performed literature review to analyze the correlation between clinical phenotypes and genotypes. Results: The clinical manifestations in the child were short stature, ulnar hypoplasia of the forearm, hypohidrosis, retracted nipple, micropenis, and cryptorchidism. Laboratory examination revealed hyperthyroidism, growth hormone deficiency, and hypogonadotropic hypogonadism. Imaging results displayed delayed bone age, small pituitary gland, and persistence of Rathke's cleft cyst. The results of the exome sequencing revealed the deletion of AGA at positions 1121-1,124 of TBX3, which resulted in a frameshift mutation (c.1121-1124del AGAG; pGlu374fs). According to the American College of Medical Genetics (ACMG) assessment, the mutation is a pathogenic variant. A definitive diagnosis of UMS was made on the basis of the clinical phenotype of the patient. The Chinese and English literature were reviewed to analyze the correlation between TBX3 genotype and clinical phenotype. Conclusion: UMS is a rare hereditary disease caused by mutations in TBX3. There is significant clinical heterogeneity associated with the variants of this gene. To our knowledge, this mutation site in TBX3 has been reported for the first time, thereby expanding the mutation spectrum of this gene.

Ezetimibe inhibits triple-negative breast cancer proliferation and promotes cell cycle arrest by targeting the PDGFR/AKT pathway.

Cholesterol levels were strongly associated with tumor progression and metastasis. Targeted cholesterol metabolism has broad prospects in tumor treatment. Ezetimibe, the only FDA-approved inhibitor of cholesterol absorption, has been reported to be able to inhibit angiogenesis in liver cancer. However, the efficacy and specific mechanisms of Ezetimibe in the treatment of Triple-Negative Breast Cancer (TNBC)have not been reported. Our research shows Ezetimibe inhibits TNBC cell proliferation and blocks the cell cycle in the G1 phase. Mechanistically, Ezetimibe inhibits the activation of PDGFRß/AKT pathway, thereby promoting cell cycle arrest and inhibiting cell proliferation. By overexpressing PDGFRß in TNBC cells, we found that PDGFRß significantly reduced the inhibitory effect of Ezetimibe on TNBC cell proliferation and the cell cycle. Similarly, SC79, an AKT agonist, can reduce the proliferation inhibitory and cycle-blocking effects of Ezetimibe on TNBC cells. Furthermore, the AKT inhibitor MK2206 enhanced the inhibitory effect of Ezetimibe on the cell cycle and proliferation ability of TNBC cells overexpressing PDGFRß. In xenograft tumor models, we also found that Ezetimibe inhibited TNBC growth, an effect that can be blocked by overexpression of PDGFR or activation of AKT. In summary, we have demonstrated that EZ inhibits the PDGFR/AKT pathway, thereby halting TNBC cycle progression and tumor growth.

A novel approach for the analysis of single-cell RNA sequencing identifies TMEM14B as a novel poor prognostic marker in hepatocellular carcinoma.

A fundamental goal in cancer-associated genome sequencing is to identify the key genes. Protein-protein interactions (PPIs) play a crucially important role in this goal. Here, human reference interactome (HuRI) map was generated and 64,006 PPIs involving 9094 proteins were identified. Here, we developed a physical link and co-expression combinatory network construction (PLACE) method for genes of interest, which provides a rapid way to analyze genome sequencing datasets. Next, Kaplan‒Meier survival analysis, CCK8 assays, scratch wound assays and Transwell assays were applied to confirm the results. In this study, we selected single-cell sequencing data from patients with hepatocellular carcinoma (HCC) in GSE149614. The PLACE method constructs a protein connection network for genes of interest, and a large fraction (80%) of the genes (screened by the PLACE method) were associated with survival. Then, PLACE discovered that transmembrane protein 14B (TMEM14B) was the most significant prognostic key gene, and target genes of TMEM14B were predicted. The TMEM14B-target gene regulatory network was constructed by PLACE. We also detected that TMEM14B-knockdown inhibited proliferation and migration. The results demonstrate that we proposed a new effective method for identifying key genes. The PLACE method can be used widely and make outstanding contributions to the tumor research field.

Effect of Phosphorus Content on Magnetic and Mechanical Properties of Non-Oriented Electrical Steel.

The effect of target phosphorus (P) content on the precipitates, microstructure, texture, magnetic properties, and mechanical properties of low-carbon (C) and low-silicon (Si) non-oriented electrical steel (NOES) was investigated and the influence mechanism was clarified. The results indicate that the precipitates in the steels are mainly aluminum (Al)-manganese (Mn)-Si-bearing complex nitrides ((Al,Si,Mn)xNy) and P-bearing complex nitrides ((Al,Si,Mn)xNy-P). Increasing target phosphorus content in the steels decreases (Al,Si,Mn)xNy, and increases (Al,Si,Mn)xNy-P. The number density of the precipitates is the lowest, and the average size of the precipitates and grain size of the finished steel is the largest in the samples with target P content at the 0.14% level (0.14%P-targeted). The average grain size and microstructure homogeneity of the steels are influenced by the addition of phosphorus. The content of the {111}<112> component decreases, and the favorable texture increases after phosphorus is added to the steel. The magnetic induction of the steel is improved. Grain refinement and microstructure inhomogeneity lead to an iron loss increase after target phosphorus content increases in the steel. The best magnetic induction B50 is 1.765 T in the 0.14%P-targeted samples. The tensile strength and yield strength are improved owing to solid solution strengthening and the grain refinement effect of phosphorus added to the steels.

The multi-functional system of electrochemical desalination, RhB degradation and Cr (VI) removal.

SYNOPSIS: : The single function of salt removal limits the further development of the CDI system. A multi-function CDI device is proposed to achieve electrochemical desalination, organics degradation and dichromate ion removal.

Photoreduction properties of novel Z-scheme structured Sr0.8La0.2(Ti1-δ 4+Ti δ 3+)O3/Bi2MoO6 composites for the removal of Cr(vi).

Novel Z-scheme structured Sr0.8La0.2(Ti1-δ 4+Ti δ 3+)O3/Bi2MoO6 (LSTBM) composites were prepared via a facile two-step solvothermal method. Several characterization techniques were employed to investigate the phases, microstructures, compositions, valence states, oxygen vacancies, surface oxygen absorption, energy band structures and lifetime of photoproduced carriers. It was found that the lifetime and transfer of the photoproduced carriers of LSTBM were better than those of Bi2MoO6 (BMO) and Sr0.8La0.2(Ti1-δ 4+Ti δ 3+)O3 (LSTO). The LSTBM with a molar ratio of BMO/(LSTO + BMO) = 0.07 (denoted as LSTBM7) showed 1.9 and 3.1 times removal rates than those for BMO and LSTO, respectively. Importantly, the built-in electric field in the heterojunction of LSTBM and Ov-s, especially in Ov-s on the higher-Fermi-level side of the heterojunction, had co-played roles in prolonging the lifetime and improving the transfer of photogenerated carriers. The photoproduced e- played a dominant role in reducing Cr(vi) to Cr(iii) and the produced Cr(iii) tends to form Cr(OH)3 and adsorb onto the surface of the photocatalyst to decrease the nucleation energy. The possible reduction route for Cr(vi) to Cr(iii) over LSTBM7 was figured out. This study implies that inducing Ov-s on the higher-Fermi-level side of the Z-scheme heterojunction is a more effective route for separating the photogenerated electrons and holes and improving the transfer of photogenerated carriers.

Photocatalytic properties of a new Z-scheme system BaTiO3/In2S3 with a core-shell structure.

It's highly desired to design and fabricate an effective Z-scheme photo-catalyst with excellent charge transfer and separation, and a more negative conduction band edge (E CB) than O2/·O2 - (-0.33 eV) and a more positive valence band edge (E VB) than ·OH/OH- (+2.27 eV) which provides high-energy redox radicals. Herein, we firstly designed and synthesized a core-shell-heterojunction-structured Z-scheme system BaTiO3@In2S3 (BT@IS, labelled as BTIS) through a hydrothermal method, where commercial BT was used as the core and In(NO3)3·xH2O together with thioacetamide as the precursor of IS was utilized as the shell material. In this system, the shell IS possesses a E CB of -0.76 eV and visible-light-response E g of 1.92 eV, while the core BT possesses a E VB of 3.38 eV, which is well suited for a Z-scheme. It was found that the as-prepared BTIS possesses a higher photocatalytic degradation ability for methyl orange (MO) than commercial BT and the as-prepared IS fabricated by the same processing parameters as those of BTIS. Holes (h+) and superoxide radicals (·O2 -) were found to be the dominant active species for BTIS. In this work, the core-shell structure has inhibited the production of ·OH because the shell IS has shielded the OH- from h+. It is assumed that if the structure of BTIS is a composite, not a core-shell structure, ·OH could be produced during photocatalysis, and therefore a higher photocatalytic efficiency would be obtained. This current work opens a new pathway for designing Z-scheme photocatalysts and offers new insight into the Z-scheme mechanism for applications in the field of photocatalysis.