TiO
2/multi-wall carbon nanotube (MWNT) heterojunction arrays were synthesized and immobilized on Si(0
0
1) substrate as photocatalysts for inactivation of
Escherichia coli bacteria. The vertically ...aligned MWNT arrays were grown on ∼5
nm Ni thin film deposited on the Si by using plasma enhanced chemical vapor deposition at 650
°C. Then, the MWNTs were coated by TiO
2 using dip-coating sol–gel method. Post annealing of the TiO
2/MWNTs at 400
°C resulted in crystallization of the TiO
2 coating and formation of Ti–C and Ti–O–C carbonaceous bonds at the heterojunction. The visible light-induced photoinactivation of the bacteria increased from MWNTs to TiO
2 to TiO
2/MWNTs, in which the bacteria could even slightly breed on the MWNTs. In addition, the TiO
2/MWNTs annealed at 400
°C showed a highly improved antibacterial activity than the TiO
2/MWNTs annealed at 100
°C. The excellent visible light-induced photocatalytic efficiency of the TiO
2/MWNTs/Si film annealed at 400
°C was attributed to formation of the carbonaceous bonds at the heterojunction, in contrast to the 100
°C annealed TiO
2/MWNTs/Si sample which had no such effective bonds.
In this work, highly stable and efficient perovskite solar cells (PSCs) in n-i-p configuration has been fabricated. Application of poly (4-vinylpyridine) (PVP) interlayer into the perovskite films ...via solution based process and quaternary semiconductor Cu2MSnS4 (M = Co2+, Ni2+, Zn2+) (CMTS) nanostructure particles as an inorganic hole transporting material (HTM), result in modified perovskite surface and improving the long term stability and the photovoltaic parameters of the PSCs. The power conversion efficiency (PCE) of the record device with Cu2ZnSnS4(CZTS) HTM and PVP interlayer reaches 13.57%, Voc gains 1.03 V, fill factor (FF) increases up to 70.64% and the device demonstrates low hysteresis (4.14%). Photoluminescence (PL), absorption spectra, electrochemical impedance spectroscopy (EIS) and FESEM images reveal that, the interface between PVP and inorganic CMTS nanostructure particles favorably can reduce non-radiative recombination and enhance Voc. In addition, the presence of hydrophobic PVP interlayer and CMTS nanostructure particles capping with PVP ligands prevent the ingress of the moisture in to the perovskite layer and result in improved stability, where the devices based on CZTS HTM, retain 97% of the initial efficiency after 30 days at room temperature and 35–40% relative humidity.
•CMTS nanostructure particles used as HTM and PVP applied as an interlayer.•Formation of PVP/CMTS nanostructure particles interface leads to passivation of the trap states.•The PCSs based on CZTS HTM retained 97% of initial efficiency during 30-day due to the presence of PVP interlayer.•CZTS-based devices with PVP interlayer reached the PCE of 13.57%, and Voc of 1.03 V, with low hysteresis.
Despite the increasing number of studies on Parkinson's disease and it being the second most common neurodegenerative disorder in the world, no established diagnostic markers or disease modifying ...therapies are available. Understanding the mechanisms involved in its pathogenesis and identifying markers capable of diagnosing or tracking progression of PD is greatly needed. Among the several factors identified to be involved in Parkinson's disease, the immune system has had increasingly growing evidence that presents a fresh avenue to investigate the pathology of the disease. The involvement of the immune system in the pathology of Parkinson's disease has been linked to an interaction between the peripheral and central nervous system immune response. Whether this involvement is due to an immune response being a cause or consequence of Parkinson's disease pathology is still a matter of debate. Players investigated include cytokines, chemokines, and immune-cells found in both the central and peripheral immune system. Herein, we discuss advances in the current literature on these immune-related markers and their potential use as markers for Parkinson's disease diagnosis and progression.
Inorganic hole transport material Cu2ZnSnS4&CNT and PVP interlayer are applied in perovskite solar cells as a degradation inhibiter. The CNT webs, act as a highly conductive connecting bridges to ...boost the charge transfer process, and the PVP passivates the surface trap states which result in higher performance and stability of PSCs.
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•PVP and inorganic HTM Cu2ZnSnS4&CNT in PSCs act as a degradation inhibiter.•CNT webs, as a conductive connecting bridges boosts the charge transfer process.•PVP passivates the surface trap states, result in higher PCE and stability of PSCs.
Organic-inorganic perovskite solar cells (PSCs) are emerging candidates for next generation photovoltaic devices. In the last decade, PSCs have depicted a rapid development in device performance, meanwhile, the issue of utilizing low-cost, non-toxic materials with chemical stability as well as long term device stabilities are still lacking. To address these issues, an inexpensive, eco-friendly, and environmentally stable nanostructure of the quaternary chalcogenide Cu2ZnSnS4 (CZTS) as an inorganic hole transport material (HTM) has been investigated. Moreover, simultaneously two strategies has been employed to optimize the photovoltaic parameters. First, an interlayer of poly(4-vinylpyridine) (PVP) has been applied between the perovskite and the hole transport layer (HTL). Second, single-walled carbon nanotubes (CNTs) is incorporated into the CZTS HTL. While, the latter only result in higher short circuit current density (Jsc) from 18.3 to 20 mA cm−2, by using both of the strategies an increase in open circuit voltage (Voc) from 0.98 to 1.05 V as well as Jsc from 18.3 to 20.5 mA cm−2 has been observed. The power conversion efficiency (PCE) of the record device reached to 15.2%, fill factor (FF) increased up to 70% and also demonstrated low hysteresis of 2.3%. The formation of hydrophobic CNT webs among the sphere-like CZTS nanostructures and the presence of the PVP polymeric interlayer results in highly stable devices, which retained more than 98% of the initial PCE at room temperature and 40–45% humidity after 30 days. Thus, our results show that the combination of PVP interlayer and CZTS&CNT HTL offer an opportunity for the scalability of PSCs.
Herein, we report that iron(II)/ammonium persulfate in aqueous acetonitrile mediates the Newman–Kwart rearrangement of O-aryl carbamothioates. Electron-rich substrates react rapidly under moderate ...heating to afford the rearranged products in excellent yields. The mild conditions, rapid reaction rates, and suitability for scale up offers immediate practical benefits to access functionalized thiophenols.
•Thin layers of anatase titanium dioxide were coated on glass by spray pyrolysis method.•The layers were hydrogenated by DC plasma from room temperature up to 350°C.•Band gap of the layers was ...decreased 0.13eV by plasma treatment at highest temperature.•There is a specific plasma temperature range, which hydrophilicity and photocatalytic properties of the layers are optimum.
Thin layers of anatase titanium dioxide were coated on glass by spray pyrolysis method. The layers were hydrogenated by DC plasma from room temperature up to 350°C. Hydrogen plasma treatment at low temperatures, leads to decrease the surface roughness, while surface roughness is increased by enhancing plasma temperature. Layers’ band gap was decreased 0.13eV by plasma treatment at highest temperature. Hydrophilicity and photocatalytic properties of the layers under plasma treatment at 150 and 200°C, were improved noticeably. However, plasma treatment at temperatures above 200°C was lead to decrease hydrophilicity and photocatalytic activity of TiO2 layers. The reason seems formation of oxygen vacancies in the interior layers that act as charge carriers’ recombination centers.
Coronavirus disease of 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has sparked a global pandemic with severe complications and high morbidity rate. ...Neurological symptoms in COVID-19 patients, and neurological sequelae post COVID-19 recovery have been extensively reported. Yet, neurological molecular signature and signaling pathways that are affected in the central nervous system (CNS) of COVID-19 severe patients remain still unknown and need to be identified. Plasma samples from 49 severe COVID-19 patients, 50 mild COVID-19 patients, and 40 healthy controls were subjected to Olink proteomics analysis of 184 CNS-enriched proteins. By using a multi-approach bioinformatics analysis, we identified a 34-neurological protein signature for COVID-19 severity and unveiled dysregulated neurological pathways in severe cases. Here, we identified a new neurological protein signature for severe COVID-19 that was validated in different independent cohorts using blood and postmortem brain samples and shown to correlate with neurological diseases and pharmacological drugs. This protein signature could potentially aid the development of prognostic and diagnostic tools for neurological complications in post-COVID-19 convalescent patients with long term neurological sequelae.
•Neurological protein signature of severe COVID-19.•Validation of Qatar severe COVID-19 neurological protein signature in independent cohorts at protein and RNA levels.•Neurological proteins signature of severe COVID-19 corelates with Neurological diseases such as Nerve Injury, Parkinson's disease, Alzheimer's disease, Amyotrophic lateral sclerosis, and Schizophrenia.•Neurological proteins signature of severe COVID-19 corelates with pharmacological drugs such as risperidone.•The risk of developing chronic neurological diseases in post-severe COVID-19 patients.
Electron transport in the porous nanostructured titanium oxide, as a main concern in the dye-sensitized solar cells, was investigated by random walk simulation. Geometrically disordered nanoparticle ...networks with random distribution of energy was generated and utilized for simulations. Dependency of the diffusion coefficient (D ef) on the nanoparticles size, grains connectivity, and the network porosity was completely studied in two cases: traps are placed mainly on the surface or in the volume of the nanoparticles. It was shown that the D ef is independent of nanoparticle size for both surface and volume diffusion. We have shown in this study that increasing the D ef with the particle size is a consequence of the trap-filling (electronic) effect and not a geometrical effect. The role of electronic effect in electron transport in nanoporous materials has been highlighted in this work.
Many loss processes in perovskite solar cells (PSCs) take place at interfaces. One effective mitigation strategy is introducing carbon derivatives at the interface of the charge transport layers with ...the halide perovskite absorber and/or with the contacts. In this work, single-walled carbon nanotubes are incorporated into the hole transporting material (HTM), either as composites or as a separate layer on top of the HTM. Both organic and inorganic hole transport materials are studied to validate this approach for different types of HTMs. It is shown that the CNTs facilitate charge transport from perovskite to the back contact, regardless of the HTM used. The use of CNTs results in an increase in a significant increase in short circuit current and power conversion efficiency. This study illustrates how SWCNTs can be utilised to improve the properties of a wide range of HTMs, which will pave the way for more efficient and PSCs.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Nonlinear recombination in dye-sensitized solar cells was studied from a fundamental point of view. A model based on Marcus theory was used to describe the recombination from both conduction band and ...trap states. By combination of this model with the empirical form of nonlinear recombination, dependency of the reaction order (β) on the microscopic parameters of the solar cell was investigated. It was analytically shown that β is always less than unity and also depends on the quasi Fermi-level in semiconductors. By this nonconstant β, the dependency of the ideality factor (m), electron diffusion length (L n ), and the electron lifetime (τ n ) on the Fermi-level were studied. It was discussed that the nonconstant β can explain the flattening of the L n at high Fermi-level, as observed in some recent experimental works. For the lifetime, it was shown that only the quantity τ n /m is accessible in the common open-circuit voltage decay method. It was also shown that the lifetime and the ideality factor can be obtained by the well-known charge extraction method.
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