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Photocatalytic oxidative coupling of methane (OCM) into value-added industrial chemicals offers an appealing green technique for achieving sustainable development, whereas it encounters double bottlenecks in relatively low methane conversion rate and severe overoxidation. Herein, we engineer a continuous gas flow system to achieve efficient photocatalytic OCM while suppressing overoxidation by synergizing the moderate active oxygen species, surface plasmon-mediated polarization, and multipoint gas intake flow reactor. Particularly, a remarkable CH4 conversion rate of 218.2 µmol h-1 with an excellent selectivity of â¼90% toward C2+ hydrocarbons and a remarkable stability over 240 h is achieved over a designed Au/TiO2 photocatalyst in our continuous gas flow system with a homemade three-dimensional (3D) printed flow reactor. This work provides an informative concept to engineer a high-performance flow system for photocatalytic OCM by synergizing the design of the reactor and photocatalyst to synchronously regulate the mass transfer, activation of reactants, and inhibition of overoxidation.
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Ternary-phase CuWO4oxide with an electronic band gap of 2.2-2.4 eV is a potential candidate photoanode material for photoelectrochemical (PEC) water splitting. Herein, we present an efficient method to prepare CuWO4film photoanode by combining hydrothermal method and hybrid microwave annealing (HMA) process. In comparison with conventional thermal annealing (CTA), HMA can achieve CuWO4thin film within minutes by using SiC susceptor. When the CuWO4photoanode is prepared by HMA, its PEC water oxidation performance improves from 0.21 to 0.29 mA cm-2at 1.23 VRHEcomparing with the one prepared by CTA. The origin of the enhanced photocurrent was investigated by means of complementary physical characterizations and PEC methods. The results demonstrated that the obtained HMA processed CuWO4photoanode not only exhibited intrinsic porous nanostructures but also abundant surface hydroxyl groups, which facilitated sufficient mass transport and the charge transfer. Our results highlight the application of HMA for the fast fabrication of porous film photo-electrodes without using sacrificial template.
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In single-atom catalysts (SACs), the complexity of the support anchoring sites creates a vast diversity of single-atom species with varied coordination environments. To date, the quantitative distribution of these diverse single-atom species in a given SAC has remained elusive. Recently, CeO2-supported metal SACs have been extensively studied by modulating their local environments via numerous synthetic strategies. However, owing to the absence of a quantitative description, unraveling the site-specific reactivity and regulating their transformation remain challenging. Here, we show that two distinct Pt/CeO2 SACs can be reversibly generated by oxidative and nonoxidative dispersions, which contain varied Pt1On-Ceδ+ single-atom species despite similar Pt charge states and coordination numbers. By means of Raman spectroscopy and computational studies, we semiquantitatively reveal the distribution of diverse Pt1On-Ceδ+ species in each specific SACs. Remarkably, the minority species of Pt1O4-Ce3+-Ov accounting for only 14.2% affords the highest site-specific reactivity for low-temperature CO oxidation among the other abundant counterparts, i.e., Pt1O4-Ce4+ and Pt1O6-Ce4+. The second nearest oxygen vacancy (Ov) not only acts synergistically with the nearby active metal sites to lower the reaction barrier but also facilitates the dynamic transformation from six-coordinated to four-coordinated sites during cyclic nonoxidative and oxidative dispersions. This work elucidates the quantitative distribution and dynamic transformation of varied single-atom species in a given SAC, offering a more intrinsic descriptor and quantitative measure to depict the inhomogeneity of SACs.
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Energetic coatings have attracted a great deal of interest with respect to their compatibility and high energy and power density. However, their preparation by effective and inexpensive methods remains a challenge. In this work, electrophoretic deposition was investigated for the deposition of an Al/CuO thermite coating as a typical facile effective and controllable method. Given the poor adhesion of the deposited film and the native inert Al2O3 shell on Al limiting energy output, further treatment was conducted by soaking in a Nafion solution, which not only acted as a fluoropolymer binder but also introduced a strong F oxidizer. It is interesting to note that the adhesion level of Al/CuO films was improved greatly from 1B to 4B, which was attributed to Nafion organic network film formation, like a fishing net covering the loose particles in the film. Combustion and energy release were analyzed using a high-speed camera and a differential scanning calorimeter. A combustion rate of ≤3.3 m/s and a heat release of 2429 J/g for Al/NFs/CuO are far superior to those of pristine Al/CuO (1.3 m/s and 841 J/g, respectively). The results show that the excellent combustion and heat release properties of the energetic film system are facilitated by the good combustion-supporting properties of organic molecules and the increase in the film density after organic treatment. The prepared Al/NFs/CuO film was also employed as ignition material to fire B-KNO3 explosive successfully. This study provides a new way to prepare organic-inorganic hybrid energetic films, simultaneously altering the energy release and enhancing the adhesive force. In addition, the Al/NFs/CuO coating also showed considerable potential as an ignition material in microignitors.
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Mixed-anion inorganic compounds offer diverse functionalities as a function of the different physicochemical characteristics of the secondary anion. The quaternary metal oxynitrides, which originate from substituting oxygen anions (O2-) in a parent oxide by nitrogen (N3-), are encouraging candidates for photoelectrochemical (PEC) water splitting because of their suitable and adjustable narrow band gap and relative negative conduction band (CB) edge. Given the known photochemical activity of LaTiO2N, we investigated the paramagnetic counterpart NdTiO2+xN1-x. The electronic structure was explored both experimentally and theoretically at the density functional theory (DFT) level. A band gap (Eg) of 2.17 eV was determined by means of ultraviolet-visible (UV-vis) spectroscopy, and a relative negative flat band potential of -0.33 V vs reversible hydrogen electrode (RHE) was proposed via Mott-Schottky measurements. 14N solid state nuclear magnetic resonance (NMR) signals from NdTiO2+xN1-x could not be detected, which indicates that NdTiO2+xN1-x is berthollide, in contrast to other structurally related metal oxynitrides. Although the bare particle-based photoanode did not exhibit a noticeable photocurrent, Nb2O5 and CoOx overlayers were deposited to extract holes and activate NdTiO2+xN1-x. Multiple electrochemical methods were employed to understand the key features required for this metal oxynitride to fabricate photoanodes.
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Mössbauerite, a trivalent iron-only layered oxyhydroxide, has been recently identified as an electrocatalyst for water oxidation. We investigated the material as potential cocatalyst for photoelectrochemical water oxidation on semiconductor photoanodes. The band edge positions of mössbauerite were determined for the first time with a combination of Mott-Schottky analysis and UV-vis diffuse reflectance spectroscopy. The positive value of the Mott-Schottky slope and the flatband potential of 0.34 V vs reversible hydrogen electrode (RHE) identifies the material as an n-type semiconductor, but bare mössbauerite does not produce noticeable photocurrent during water oxidation. Type-II heterojunction formation by facile drop-casting with WO3 thin films yielded photoanodes with amended charge carrier separation and photocurrents up to 1.22 mA cm-2 at 1.23 V vs RHE. Mössbauerite is capable of increasing the charge carrier separation at lower potential and improving the photocurrent during photoelectrochemical water oxidation. The rise in photocurrent of the mössbauerite-functionalized WO3 photoanode thus originates from improved charge carrier separation and augmented hole collection efficiency. Our results highlight the potential of mössbauerite as a second-phase catalyst for semiconductor electrodes.
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CuWO4 is a photoanode candidate in neutral pH, and manganese-based oxygen evolution reaction electrocatalysts are of high interest due to their low price and low toxicity. Considering the unexplored chemistry of transition-metal carbodiimides/cyanamides for the PEC water oxidation, we investigated MnNCN as an electrocatalyst for CuWO4 under AM 1.5G illumination in potassium phosphate electrolyte (pH 7). Surface functionalization of CuWO4 photoanodes with MnNCN increased the photocurrent from 22 to 30 µA cm-2 at 1.23 V vs RHE. Complementary structural analysis by means of XRD and XPS revealed that MnNCN forms a core-shell structure MnNCN@MnPO x in phosphate electrolyte and mimics a manganese phosphate electrocatalyst. As such, the surface chemistry of MnNCN significantly differs from previous studies on the cobalt analogue (CoNCN). A separately prepared MnNCN electrode developed a small but detectable photocurrent due to photogenerated holes inside the semiconducting carbodiimide core of the MnNCN@MnPO x structure.
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To investigate the influence of dietary taurine and reduced housing density on hepatic functions in laying hens, green-shell laying hens were randomly assigned to 3 groups: a free-range group, a caged group with low-density, and a caged group with high-density. Each group was further divided into the control (C) and taurine-treatment (T) groups. All the test birds were fed the same basic diet, except that the T groups were supplemented with 0.1% taurine. After 15 d, sera and liver were aseptically collected. The results show that dietary taurine supplementation and reduced housing density significantly attenuated physiopathological changes in the liver. When compared with the free-range group, serum alanine aminotransterase and aspartate aminotransterase in the caged hens were significantly higher and were deceased by taurine (P < 0.05). Serum inducible nitric oxide synthase activity in caged hens was higher than that in free-range hens, and taurine reduced serum inducible nitric oxide synthase activities in the low-density group (P < 0.05). Nuclear factor-κB DNA-binding activity increased significantly in the high-density housing group when compared with the other 2 housing patterns and was decreased by taurine (P < 0.05). Taurine reduced the expression of tumor necrosis factor-α mRNA in all 3 rearing patterns, IL-4 mRNA expression in the high-density group, and IL-10 in the low-density group (P < 0.05). Malondialdehyde levels decreased in serum and liver from T groups and serum total antioxidation capability levels increased significantly (P < 0.05) in the low-density group. Dietary taurine supplementation decreased acetyl-CoA and sterol regulatory element-binding protein-1c mRNA expression in the high-density groups (P < 0.05). Taurine significantly increased lipoprotein lipase mRNA expression in the high-density group and peroxisome proliferator receptor mRNA expression both in the low- and high-density groups (P < 0.05). Taurine supplementation reduced total cholesterol levels in the low- and high-density groups, decreased triglyceride and low-density lipoprotein cholesterol levels in high-density groups, and increased high-density lipoprotein cholesterol levels in all 3 rearing patterns (P < 0.05). Our data demonstrate that dietary taurine and reduced housing density offer significant protection from hepatic damage in laying hens.
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Pollos/metabolismo , Dieta/veterinaria , Suplementos Dietéticos , Vivienda para Animales , Taurina , Alanina Transaminasa/metabolismo , Alimentación Animal/normas , Animales , Aspartato Aminotransferasas/metabolismo , Proteínas Aviares/metabolismo , Femenino , Hígado/citología , Hígado/enzimología , Actividad Motora , Óxido Nítrico Sintasa de Tipo II/metabolismoRESUMEN
Nb3O7(OH) containing abundant surface lattice hydroxyl groups, combining with loaded Au nanoparticles as the cocatalyst, was employed as a photocatalyst enabling highly efficient photocatalytic CH4 coupling to C2H6 under mild conditions. In situ spectroscopy technique revealed that the surface lattice hydroxyl groups play a vital role in promoting the activation of CH4 to produce the methoxy intermediates, contributing to significantly enhanced catalytic performance for CH4 conversion.
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The optotransfection of cells based on a femtosecond laser has attracted much attention owing to its high transfection efficiency and high cell viability since its first report by Konig. However, the low throughput in the original method also limits its use in practical applications. Gold nanoparticles (GNPs) have been reported to function as local receivers of light to relax the requirement of accurate optical alignment for the optotransfection of single cells. However, the visible light used in such work is not suitable for penetrating deep tissues in certain applications. In this study, we employed gold nanorods (GNRs) and an infrared femtosecond laser at the wavelength of 980 nm to realize optotransfection of cells with GFP. It was found that the surface coating of GNRs exhibited a significant effect on the process of cell permeabilization.
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Membrana Celular/efectos de la radiación , Rayos Láser , Nanopartículas del Metal/química , Nanotubos , Transfección/métodos , Membrana Celular/fisiología , Permeabilidad de la Membrana Celular , Supervivencia Celular , Endocitosis , Oro , Células Hep G2 , Humanos , Rayos Infrarrojos , Plásmidos , Polietilenglicoles , Factores de TiempoRESUMEN
Objective: This study aimed to assess the efficacy of individual-donation nucleic acid testing (ID-NAT) in detecting occult hepatitis B virus infection (OBI) among anti-HBc positive blood donors, compared to minipool nucleic acid testing (MP-NAT). Methods: The present study analyzed data from the Shandong Blood Center in China during the period from January 2018 to June 2022, where HBsAg-negative blood donors were screened using the 6-sample minipool nucleic acid testing (6-sample MP NAT) method. NAT-positive samples underwent subsequent anti-HBc and anti-HBs testing. Approximately 5000 samples that passed the nucleic acid mixing test were randomly selected for anti-HBc testing, and over 100 anti-HBc positive samples underwent individual donor nucleic acid testing (ID-NAT). Any HBV DNA positive samples detected by ID-NAT were subsequently confirmed using alternative nucleic acid testing methods. Results: Among 220,445 HBsAg-negative blood donors, the positivity rate of HBV DNA detection using the 6-sample minipool nucleic acid testing (MP NAT) method was found to be 0.031% (69/220,445). Of the 67 HBV DNA positive samples, 55 (82.09%) and 25 (37.31%) were found to be positive for anti-HBc and anti-HBs, respectively, using the supplementary chemiluminescent microparticle immunoassay (CMIA). Among the 4797 HBsAg-negative/MP NAT-negative samples, 909 (18.95%) tested positive for anti-HBc. Further NAT testing was performed on 164 arbitrarily selected anti-HBc-positive/MP HBV DNA-negative samples, revealing a HBV DNA positivity rate of 1.22% (2/164). Conclusion: Using individual donation nucleic acid testing can significantly increase the detection rate of occult hepatitis B virus infection in anti-HBc-positive blood donors, resulting in a detection rate of 0.22% (1.22 × 0.1895). This rate is 8.10 times higher than the detection rate achieved by mixed testing methods (0.031%) [calculated as (0.22 + 0.031)/0.031]. Therefore, it is recommended to perform single HBV DNA testing on anti-HBc-positive blood donors, discard plasma with weakly positive or negative anti-HBs but positive anti-HBc, or avoid transfusing anti-HBc-positive plasma to recipients with weakly positive or negative anti-HBs to prevent HBV infection.
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We describe the synthesis, crystal structure and semiconducting properties of a number of hexacyanidometallates with the formula A2[MFe(CN)6]·xH2O (A = Na, K; M = Mg, Ca, Sr and Ba). All crystal structures were studied via single-crystal or powder X-ray diffraction. The unexpectedly low-symmetric structures in these ferrocyanides are described and contrasted with analogous transition-metal compounds which have been reported to be strictly or nearly cubic. The amount of crystal water in the structure for powder samples was determined by the thermogravimetric analysis (TGA), supported by IR and Raman spectroscopy. Electronic-structure calculations of K2[MgFe(CN)6] and K2[CaFe(CN)6] are compared with experimental UV-Vis measurements. The large band gaps by advanced theory indicate that the smaller experimental band gaps are due to surface effects of impurity states. Mott-Schottky curves of K2[MgFe(CN)6], K2[CaFe(CN)6] and K2[BaFe(CN)6]·3H2O exhibit positive slopes, which characterizes these compounds as n-type semiconductors.
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Currently, the incidence of acute liver injury (ALI) is increasing year by year, and infection with coronavirus disease 2019 (COVID-19) can also induce ALI, but there are still no targeted therapeutic drugs. ZnO-NiO particles is mainly used to clean up reactive oxygen species (ROS) in industrial wastewater, and it is insoluble in water. Its excellent properties are discovered and improved by adding shuttle-based bonds to make it more water-soluble. ZnO-NiO@COOH particles are synthetically applied to treat ALI. The p-n junction in ZnO-NiO@COOH increases the surface area and active sites, thereby creating large numbers of oxygen vacancies, which can quickly adsorb ROS. The content in tissues and serum levels of L-glutathione (GSH) and the GSH/oxidized GSH ratio are measured to assess the capacity of ZnO-NiO@COOH particles to absorb ROS. The ZnO-NiO@COOH particles significantly reduce the expression levels of inflammatory factors (i.e., IL-1, IL-6, and TNF-α), macrophage infiltration, and granulocyte activation. ZnO-NiO@COOH rapidly adsorb ROS in a short period of time to block the generation of inflammatory storms and gain time for the follow-up treatment of ALI, which has important clinical significance.
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COVID-19 , Óxido de Zinc , Glutatión , Humanos , Hígado , Níquel/química , Especies Reactivas de Oxígeno/metabolismo , Agua , Óxido de Zinc/químicaRESUMEN
Background: Homocysteine (Hcy) was implicated in oxidative stress and diabetes biologically. However, the clinical evidence on the link between Hcy level and diabetes is limited and controversial. This study is aimed at investigating the association of serum Hcy with all-cause and cardiovascular mortality in diabetic patients. Methods: Serum Hcy was measured among 2,286 adults with type 2 diabetes in NHANES 1999-2006. Cox proportional hazard regression was used to estimate hazard ratios (HR) and 95% CIs for the association of Hcy with all-cause and cause-specific mortality. Results: Over a median follow-up of 11.0 (interquartile range, 8.9-13.4) years, 952 of the 2286 patients with diabetes died, covering 269 (28.3%) cardiovascular deaths and 144 (15.2%) cancer deaths. Restricted cubic spline showed the linear relationship between Hcy and all-cause mortality risk. After multivariate adjustment, higher serum Hcy levels were independently associated with increased risk of all-cause and cardiovascular mortality. Compared with participants in the bottom tertile of Hcy, the multivariate-adjusted HRs and 95% CI for participants in the top quartile were 2.33 (1.64-3.30) for all-cause mortality (p trend < 0.001), 2.24 (1.22-4.10) for CVD mortality (p trend = 0.017), and 2.05 (0.90-4.69) for cancer mortality (p trend = 0.096). The association with total mortality was especially stronger among patients with albuminuria. Serum Hcy significantly improved reclassification for 10-year mortality in diabetic patients (net reclassification index = 0.253 and integrated discrimination improvement = 0.011). Conclusions: Serum Hcy was associated with risks of all-cause and cardiovascular mortality in diabetic adults. Our results suggested that Hcy was a promising biomarker in risk stratification among diabetic patients.
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Enfermedades Cardiovasculares , Diabetes Mellitus Tipo 2 , Neoplasias , Humanos , Adulto , Encuestas Nutricionales , Estudios Prospectivos , Diabetes Mellitus Tipo 2/complicaciones , Homocisteína , Biomarcadores , Neoplasias/complicaciones , Factores de RiesgoRESUMEN
The present study aimed to investigate the protective effects and molecular mechanisms of Dendrobium officinale polysaccharides on gastric mucosal injuries. Following one week of continuous intragastric administration, a gastric mucosal injury model was established using intragastric administration of anhydrous ethanol. The area of gastric ulcer was measured, the contents of interleukin- 6 (IL-6), epidermal growth factor receptor (EGFR), and thyroid transcription factor 1 (TFF-1) in serum were detected by enzyme linked immunosorbent assay (ELISA), and the expressions of EGFR, TFF-1, IL-6, Raf-2, MAP kinase kinase 1 (MEK1), MEK2, and ERK1 in the gastric tissue were determined utilizing qPCR, Western blotting and immunohistochemistry. Simultaneously, Dendrobium officinale polysaccharides and anhydrous ethanol were added to the gastric mucosal cells (GES1) cultured in vitro, and the protective effects of Dendrobium officinale polysaccharides on cell viability was detected using Cell Counting Kit (CCK)-8. The addition of Dendrobium officinale polysaccharides markedly improved the gastric epithelial defect, inflammatory cell infiltration, and redness and swelling stemmed from gastric mucosal injuries and greatly reduced the area of gastric ulcer. The inhibition rates of gastric ulcer were 48.12 ± 2.98, 42.95 ± 1.52, and 27.96 ± 2.05% in the high, medium, and low concentration Dendrobium officinale polysaccharide groups, respectively. Dendrobium officinale polysaccharides could increase the expressions of EGFR and TFF-1 and decrease the expressions of IL-6, Raf-2, MEK1, MEK2, and ERK1. Dendrobium officinale polysaccharides could reduce the level of inflammatory factors and protect gastric mucosa by inhibiting the expression of MAPK pathway genes and proteins.
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Antiinflamatorios/administración & dosificación , Dendrobium/química , Etanol/efectos adversos , Mucosa Gástrica/citología , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Polisacáridos/administración & dosificación , Úlcera Gástrica/tratamiento farmacológico , Animales , Antiinflamatorios/farmacología , Línea Celular , Supervivencia Celular , Modelos Animales de Enfermedad , Mucosa Gástrica/efectos de los fármacos , Regulación de la Expresión Génica/efectos de los fármacos , Genes erbB-1/efectos de los fármacos , Humanos , Interleucina-6/metabolismo , Masculino , Extractos Vegetales , Polisacáridos/farmacología , Ratas , Úlcera Gástrica/inducido químicamente , Úlcera Gástrica/metabolismo , Úlcera Gástrica/patología , Factor Trefoil-1/efectos de los fármacos , Factor Trefoil-1/metabolismoRESUMEN
We investigated the hydride reduction of tetragonal BaTiO3 using LiH. The reactions employed molar H : BaTiO3 ratios of 1.2, 3, and 10 and variable temperatures up to 700 °C. The air-stable reduced products were characterized by powder X-ray diffraction (PXRD), scanning electron microscopy, thermogravimetric analysis (TGA), X-ray fluorescence (XRF), and 1H magic-angle spinning (MAS) NMR spectroscopy. Effective reduction, as indicated by the formation of dark blue to black colored, cubic-phased, products was observed at temperatures as low as 300 °C. The product obtained at 300 °C corresponded to oxyhydride BaTiOâ¼2.9Hâ¼0.1, whereas reduction at higher temperatures resulted in simultaneous O defect formation, BaTiO2.9-x H0.1â¡ x , and eventually - at temperatures above 450 °C - to samples void of hydridic H. Concomitantly, the particles of samples reduced at high temperatures (500-600 °C) display substantial surface alteration, which is interpreted as the formation of a TiO x (OH) y shell, and sintering. Diffuse reflectance UV-VIS spectroscopy shows broad absorption in the VIS-NIR region, which is indicative of the presence of n-type free charge carriers. The size of the intrinsic band gap (â¼3.2 eV) appears only slightly altered. Mott-Schottky measurements confirm the n-type conductivity and reveal shifts of the conduction band edge in the LiH reduced samples. Thus LiH appears as a versatile reagent to produce various distinct forms of reduced BaTiO3 with tailored electronic properties.
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Metal nitrides have been suggested as prospective catalysts for the electrochemical nitrogen reduction reaction (NRR) in order to obtain ammonia at room temperature under ambient pressure. Herein, we report that templated chromium nitride porous microspheres built up by nanocubes (NCs) are an efficient noble-metal-free electrocatalyst for NRR. The CrN NCs catalyst exhibits both a high stability and NH3 yield of 31.11 µg h-1 mgcat.-1 with a Faradaic efficiency (FE) of 16.6% in 0.1 M HCl electrolyte. Complementary physical characterization techniques demonstrate partial oxidation of the pristine CrN NCs during reaction. Structural characterization by means of scanning transmission electron microscopy (STEM) combining electron energy loss spectrum (EELS) and energy dispersive X-ray spectroscopy (EDX) analysis reveals the NC structure to consist of an O-rich core and N-rich shell after NRR. This gradient distribution of nitrogen within the CrN NCs upon completed NRR is distinct to previously reported metal nitride NRR catalysts, because no significant loss of nitrogen occurs at the catalyst surface.
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Lead cyanamide PbNCN was synthesized by solid-state metathesis between PbCl2 and Na2NCN in a 1 : 1 molar ratio, and its structure was confirmed from Rietveld refinement of X-ray data. Electronic-structure calculations of HSE06 density-functional type reveal PbNCN to be an indirect semiconductor with a band gap of 2.4 eV, in remarkable quantitative agreement with the measured value. Mott-Schottky experiments demonstrate PbNCN to be a p-type semiconductor with a flat-band potential of 2.3 eV vs. the reversible hydrogen electrode (RHE) which is commonly used to estimate the value of the valence band edge position. Moreover, thin films of powderous PbNCN were assembled into a photoelectrode for photoelectrochemical water splitting. On the example of p-type PbNCN, this study provides the first experimental evidence that MNCN compounds can be applied as photocathodes for reductive reactions in photoelectrochemical cells.
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Conjugated polymers are emerging as alternatives to inorganic semiconductors for the photoelectrochemical water splitting. Herein, semi-transparent poly(4-alkylthiazole) layers with different trialkylsilyloxymethyl (R3SiOCH2-) side chains (PTzTNB, R = n-butyl; PTzTHX, R = n-hexyl) are applied to functionalize NiO thin films to build hybrid photocathodes. The hybrid interface allows for the effective spatial separation of the photoexcited carriers. Specifically, the PTzTHX-deposited composite photocathode increases the photocurrent density 6- and 2-fold at 0 V versus the reversible hydrogen electrode in comparison to the pristine NiO and PTzTHX photocathodes, respectively. This is also reflected in the substantial anodic shift of onset potential under simulated Air Mass 1.5 Global illumination, owing to the prolonged lifetime, augmented density, and alleviated recombination of photogenerated electrons. Additionally, coupling the inorganic and organic components also enhances the photoabsorption and amends the stability of the photocathode-driven system. This work demonstrates the feasibility of poly(4-alkylthiazole)s as an effective alternative to known inorganic semiconductor materials. We highlight the interface alignment for polymer-based photoelectrodes.
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Tin(ii) oxide carbodiimide is a novel prospective semiconductor material with a band gap of 2.1 eV and lies chemically between metal oxides and metal carbodiimides. We report on the photochemical properties of this oxide carbodiimide and apply the material to form a heterojunction with CuWO4 thin films for photoelectrochemical (PEC) water oxidation. Mott-Schottky experiments reveal that the title compound is an n-type semiconductor with a flat-band potential of -0.03 V and, as such, the position of the valence band edge would be suitable for photochemical water oxidation. Sn2O(NCN) increases the photocurrent of CuWO4 thin films from 32 µA cm-2 to 59 µA cm-2 at 1.23 V vs. reversible hydrogen electrode (RHE) in 0.1 M phosphate buffer (pH 7.0) under backlight AM 1.5G illumination. This upsurge in photocurrent originates in a synergistic effect between the oxide and oxide carbodiimide, because the heterojunction photoanode displays a higher current density than the sum of its individual components. Structural analysis by powder X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) reveals that Sn2O(NCN) forms a core-shell structure Sn2O(NCN)@SnPOx during the PEC water oxidation in phosphate buffer. The electrochemical activation is similar to the behavior of Mn(NCN) but different from Co(NCN).