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1.
Photochem Photobiol Sci ; 22(10): 2357-2371, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37440001

RESUMO

Luminescent lanthanide (Ln3+ = Pr, Nd, Sm, Eu, and Tb)-ions doped calcium molybdate(CaMoO4) nanoparticles(NPs) were prepared by the polyol wet-chemical route. X-ray diffraction (XRD) pattern of all samples showed the formation of a single-phase scheelite type tetragonal structure with an average crystalline size over 21.6-33.4 nm. Thermal stability was evaluated to study the surface-anchored functional groups by weight loss measurement. Fourier transform infrared (FTIR) spectra were recorded to identify the adsorbed functional groups. Aqueous dispersibility and colloidal stability were recorded with the help of the UV/visible absorption spectra. These nanocrystals formed semi-transparent colloidal solutions after being evenly disseminated in aqueous media. The doping of the luminescent ions significantly affects the crystal structure and photoluminescence (PL) properties of the CaMoO4:Ln3+ NPs. In a comparative analysis of the absorption spectra, bandgap, Raman-active modes, and luminescent properties, they were greatly influenced by altering the dopant ion due to the variation in the atomic radius of the element. The doping of smaller atomic radius Ln3+-ions distorts the unit cell, and, subsequently, bond angle/length alters the symmetry of the host crystal. The distorted crystal lattice affects the crystalline, size, lattice parameter, band gap values, Raman active vibrational modes, and luminescent efficiency. The distorted crystal structure of the host lattices facilitates the movement of the oxygen vacancies through charge transfer, resulting in efficiently suppressed emission efficiency.Graphical abstract.

2.
Environ Res ; 216(Pt 3): 114712, 2023 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-36334832

RESUMO

The use of photocatalysts for acquiring direct photon energy from sunlight is a promising way to clean the environment, particularly the remediation of contaminants from water. In this work, firstly π-conjugated organic semiconductor configuring benzoselenadiazole, 4-(3,5-bis(trifluoromethyl) phenyl)-7-(5'-hexyl-[2,2'-bithiophen]-5-yl)-benzo [c] (Kümmerer, 2009; Chen et al., 2018; Randeep et al., 201) selenadiazole, abbreviated as (RTh-Se-F), was synthesized. The designed RTh-Se-F with an extended π-conjugation showed good optical properties in the visible region and estimated a low optical band gap of ∼2.02 eV . The molecular orbitals i.e. HOMO (-5.33 eV) and LUMO (-3.31 eV) for RTh-Se-F organic semiconductor were suitably aligned to energy levels of (Madhavan et al., 2010Madhavan et al., 2010)-Phenyl-C71-butyric acid methyl esters (PC71BM) which resulted in the broadening of absorption and covering of entire visible region. RTh-Se-F was integrated with varied weight percentages (wt %) of PC71BM to obtain bulk heterojunction (BHJ) and applied as efficient visible light driven BHJ photocatalyst for an effective oxidation of ibuprofen. RTh-Se-F@PC71BM (1:2, wt %) BHJ photocatalyst showed the superior ibuprofen degradation of ∼93% within 90 min under visible light illumination. The maximum degradation rate by BHJ photocatalyst might be accredited to the broadening of absorption capacity and improved lifetime of photogenerated electron-hole pairs which might be resulted from high absorption properties of RTh-Se-F organic semiconductor.


Assuntos
Ibuprofeno , Luz , Catálise , Oxirredução
3.
Sensors (Basel) ; 23(18)2023 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-37765968

RESUMO

A simple hydrothermal synthesis approach was used to synthesize porous MgNiO2 Chrysanthemum Flowers (CFs) nanostructures and applied as a sensing electrode for quick detection of hazardous mercury (Hg2+ ions). The morphological, structural, and electrochemical properties of MgNiO2 CFs were investigated. The morphological characteristic of MgNiO2 CFs, with a specific surface area of 45.618 m2/g, demonstrated strong electrochemical characteristics, including cations in different oxidation states of Ni3+/Ni2+. Using a three-electrode system for electrochemical detection, the MgNiO2 CFs based electrode revealed a good correlation coefficient (R2) of ~0.9721, a limit of detection (LOD) of ~11.7 µM, a quick response time (10 s), and a sensitivity of 8.22 µA∙µM-1∙cm-2 for Hg2+ ions over a broad linear range of 10-100 µM. Moreover, the selectivity for Hg2+ ions in tap water and drinking water was determined, and a promising stability of 25 days by MgNiO2 CFs electrode was exhibited. The obtained results indicate that the developed MgNiO2 CFs are a promising electrode for detecting hazardous Hg2+ ions in water and have the potential to be commercialized in the future.

4.
Bioinformatics ; 37(11): 1635-1636, 2021 07 12.
Artigo em Inglês | MEDLINE | ID: mdl-33119075

RESUMO

MOTIVATION: Mass spectrometry-based phosphoproteomics can routinely identify and quantify thousands of phosphorylated peptides from a single experiment. However interrogating possible upstream kinases and identifying key literature for phosphorylation sites is laborious and time-consuming. RESULTS: Here, we present Phosphomatics-a publicly available web resource for interrogating phosphoproteomics data. Phosphomatics allows researchers to upload phosphoproteomics data and interrogate possible relationships from a substrate-, kinase- or pathway-centric viewpoint. AVAILABILITY AND IMPLEMENTATION: Phosphomatics is freely available via the internet at: https://phosphomatics.com. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.


Assuntos
Fosfotransferases , Proteômica , Espectrometria de Massas , Software
5.
Langmuir ; 30(43): 12786-94, 2014 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-25296009

RESUMO

A high performance perovskite solar cell was fabricated using the distinguished morphology of polyaniline nanoparticles (PANI-NPs) as an efficient hole transporting layer (HTL) with methylammonium lead iodide perovskite (CH3NH3PbI3) as sensitizer. PANI-NPs were simply synthesized by the oxidative chemical polymerization of aniline monomer at 0-5 °C. A reasonable solar-to-electricity conversion efficiency of ∼6.29% with a high short circuit current (JSC) of ∼17.97 mA/cm(2) and open circuit voltage (VOC) of ∼0.877 V were accomplished by Ag/PANI-NPs/CH3NH3PbI3/mp-anatase-TiO2/bl-TiO2/FTO perovskite solar cell. The transient photocurrent and photovoltage studies revealed that the fabricated solar cell showed better charge transport time, diffusion coefficient, diffusion length, and charge collection efficiency. Herein, the use of PANI-NPs as the HTL improved the charge carrier generation and the charge collection efficiency of the fabricated solar cell.

6.
Micromachines (Basel) ; 15(4)2024 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-38675252

RESUMO

In this study, well-defined tungsten oxide (WO3) nanowall (NW) thin films were synthesized via a controlled hot filament chemical vapor deposition (HFCVD) technique and applied for electrochemical detection of methylamine toxic substances. Herein, for the thin-film growth by HFCVD, the temperature of tungsten (W) wire was held constant at ~1450 °C and gasification was performed by heating of W wire using varied substrate temperatures ranging from 350 °C to 450 °C. At an optimized growth temperature of 400 °C, well-defined and extremely dense WO3 nanowall-like structures were developed on a Si substrate. Structural, crystallographic, and compositional characterizations confirmed that the deposited WO3 thin films possessed monoclinic crystal structures of high crystal quality. For electrochemical sensing applications, WO3 NW thin film was used as an electrode, and cyclic voltammetry (CV) and linear sweep voltammetry (LSV) were measured with a wide concentration range of 20 µM~1 mM of methylamine. The fabricated electrochemical sensor achieved a sensitivity of ~183.65 µA mM-1 cm-2, a limit of detection (LOD) of ~20 µM and a quick response time of 10 s. Thus, the fabricated electrochemical sensor exhibited promising detection of methylamine with considerable stability and reproducibility.

7.
Chemosphere ; 357: 141961, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38615954

RESUMO

Microplastics (MPs) poses a significant threat to ecosystems and human health, demanding immediate attention. The reported research work offers an effective and low cost method towards the detection of toxic MPs. In this study, hydrophobic cerium oxide nanoparticles (CeO2 NPs) are synthesized and applied as promising electrode material for the detection of two different types of MPs, i.e. polyethylene (PE) and polypropylene (PP). Through electrochemical analyses, such as cyclic voltammetry (CV) and linear sweep voltammetry (LSV), hydrophobic CeO2 NPs modified glassy carbon electrode (GCE) based sensor demonstrated remarkable sensitivity of ∼0.0343 AmLmg-1cm-2 and detection limit of ∼0.226 mgmL-1, with promising correlation coefficient (R2) towards the detection of PE (∼27-32 µm). Furthermore, hydrophobic CeO2 NPs modified GCE exhibited promising stability and reproducibility towards PE (∼27-32 µm), suggesting the promising potential of hydrophobic CeO2 NPs as electrode materials for an electrochemical microplastics detection.


Assuntos
Cério , Monitoramento Ambiental , Interações Hidrofóbicas e Hidrofílicas , Microplásticos , Poluentes Químicos da Água , Cério/química , Poluentes Químicos da Água/análise , Microplásticos/análise , Monitoramento Ambiental/métodos , Nanopartículas/química , Técnicas Eletroquímicas/métodos , Eletrodos , Polietileno/química , Reprodutibilidade dos Testes , Nanopartículas Metálicas/química , Polipropilenos/química , Limite de Detecção
8.
Chemosphere ; 351: 141151, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38199498

RESUMO

In recent times, microplastics have become a disturbance to both aquatic and terrestrial ecosystems and the ingestion of these particles can have severe consequences for wildlife, aquatic organisms, and even humans. In this study, two types of biochars were manufactured through the carbonization of naturally found starfish (SF-1) and aloevera (AL-1). The produced biochars were utilized as sensing electrode materials for the electrochemical detection of ∼100 nm polystyrene microplastics (PS). SF-1 and AL-1 based biochars were thoroughly analyzed in terms of morphology, structure, and composition. The detection of microplastics over biochar based electrodes was carried out by electrochemical studies. From electrochemical results, SF-1 based electrode exhibited the detection efficiency of ∼0.2562 µA/µM∙cm2 with detection limit of ∼0.44 nM whereas, a high detection efficiency of ∼3.263 µA/µM∙cm2 was shown by AL-1 based electrode and detection limit of ∼0.52 nM for PS (100 nm) microplastics. Process contributed to enhancing the sensitivity of AL-1 based electrode might associate to the presence of metal-carbon framework over biochar's surfaces. The AL-1 biochar electrode demonstrated excellent repeatability and detection stability for PS microplastics, suggesting the promising potential of AL-1 biochar for electrochemical microplastics detection.


Assuntos
Carvão Vegetal , Microplásticos , Poliestirenos , Humanos , Poliestirenos/química , Plásticos , Ecossistema , Efrina-A5 , Eletrodos
9.
Heliyon ; 9(9): e19929, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37809900

RESUMO

A sensor can be called ideal or perfect if it is enriched with certain characteristics viz., superior detections range, high sensitivity, selectivity, resolution, reproducibility, repeatability, and response time with good flow. Recently, biosensors made of nanoparticles (NPs) have gained very high popularity due to their excellent applications in nearly all the fields of science and technology. The use of NPs in the biosensor is usually done to fill the gap between the converter and the bioreceptor, which is at the nanoscale. Simultaneously the uses of NPs and electrochemical techniques have led to the emergence of biosensors with high sensitivity and decomposition power. This review summarizes the development of biosensors made of NPssuch as noble metal NPs and metal oxide NPs, nanowires (NWs), nanorods (NRs), carbon nanotubes (CNTs), quantum dots (QDs), and dendrimers and their recent advancement in biosensing technology with the expansion of nanotechnology.

10.
Micromachines (Basel) ; 14(12)2023 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-38138351

RESUMO

Risedronate sodium (RIS) exhibits limited bioavailability and undesirable gastrointestinal effects when administered orally, necessitating the development of an alternative formulation. In this study, mPEG-coated nanoparticles loaded with RIS-HA-TCS were created for osteoporosis treatment. Thiolated chitosan (TCS) was synthesized using chitosan and characterized using DSC and FTIR, with thiol immobilization assessed using Ellman's reagent. RIS-HA nanoparticles were fabricated and conjugated with synthesized TCS. Fifteen batches of RIS-HA-TCS nanoparticles were designed using the Box-Behnken design process. The nanoparticles were formulated through the ionic gelation procedure, employing tripolyphosphate (TPP) as a crosslinking agent. In silico activity comparison of RIS and RIS-HA-TCS for farnesyl pyrophosphate synthetase enzyme demonstrated a higher binding affinity for RIS. The RIS-HA-TCS nanoparticles exhibited 85.4 ± 2.21% drug entrapment efficiency, a particle size of 252.1 ± 2.44 nm, and a polydispersity index of 0.2 ± 0.01. Further conjugation with mPEG resulted in a particle size of 264.9 ± 1.91 nm, a PDI of 0.120 ± 0.01, and an encapsulation efficiency of 91.1 ± 1.17%. TEM confirmed the spherical particle size of RIS-HA-TCS and RIS-HA-TCS-mPEG. In vitro release studies demonstrated significantly higher release for RIS-HS-TCS-mPEG (95.13 ± 4.64%) compared to RIS-HA-TCS (91.74 ± 5.13%), RIS suspension (56.12 ± 5.19%), and a marketed formulation (74.69 ± 3.98%). Ex vivo gut permeation studies revealed an apparent permeability of 0.5858 × 10-1 cm/min for RIS-HA-TCS-mPEG, surpassing RIS-HA-TCS (0.4011 × 10-4 cm/min), RIS suspension (0.2005 × 10-4 cm/min), and a marketed preparation (0.3401 × 10-4 cm/min).

11.
Chemosphere ; 286(Pt 2): 131695, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34426124

RESUMO

This work narrates the preparation of efficient nanomaterials framework of zinc oxide (ZnO) nanoglobules (NGs) with graphene oxide (GO) and reduced graphene oxide (rGO) for the fabrication of rapid multiple ion field-effect transistor (MI-FET) sensors. Prepared ZnO-NGs@GO and ZnO-NGs@rGO nanocomposites were broadly analyzed by different analytical techniques to study their morphological, structural, compositional, and electrochemical properties. As electrode materials, ZnO-NGs@GO and ZnO-NGs@rGO were used to fabricate MI-FETs sensor for the detection of multiple ions such as Ni (II), Co (II), Cu (II), Cr (III), Fe (II), and Bi (II) ions. ZnO-NGs@GO and ZnO-NGs@rGO modified MI-FETs sensor exhibited excellent responses towards Cr (III) and Cu (II) ions, which presented the remarkable sensitivities of ~49.28 mA µM-1. cm-2 (Cr (III) ions) and ~185.32 mA µM-1. cm-2 (Cu (II) ions), respectively. The fabricated MI-FETs sensor displayed good dynamic linear detection of ions with low limit of detection (LOD) values of ~7.05 µM and ~14.9 µM for ZnO-NGs@GO and ZnO-NGs@rGO electrodes, respectively. Efficient charge transfer over electrode considerably enhanced the trace detection of Cr (III) and Cu (II) ions. The fabricated MI-FETs sensor platform exhibited extraordinary reproducibility and excellent stability of sensing performance and thus, confirmed delightful potential to sprout a useful tool for water maintaining system.


Assuntos
Grafite , Óxido de Zinco , Íons , Reprodutibilidade dos Testes
12.
J Nanosci Nanotechnol ; 11(1): 541-5, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21446493

RESUMO

The novel organic-inorganic nanocomposites were synthesized via in-situ polymerization of polyaniline (PANI) with mesoporous silica (MCM-41) for methylene blue (MB) dye degradation under visible light. The synthesized PANI/MCM-41 nanocomposites were characterized through Fourier transform infrared (FTIR), X-ray diffraction (XRD), Raman spectroscopy, field emission scanning electron microscopy (FESEM), and UV-visible studies. The structural and optical properties confirmed the interaction between PANI and MCM-41. The photocatalytic experiments showed that the MB dye was efficiently degraded by approximately 70% under light irradiation over the surface of the PANI/MCM-41 nanocomposites. The degradation might occur due to the efficient charge separation of the e(-)-h+ pairs at the interface of PANI and MCM-41 in the excited state under light irradiation.

13.
J Nanosci Nanotechnol ; 11(2): 1559-64, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21456236

RESUMO

An inorganic/organic hetrostructure diode was constructed by the electrophoretic deposition of the p-type polyaniline (PANI) on an n-type titanium oxide (TiO2) nanoparticulate thin film. The bonding and internalization of PANI to TiO2 nanoparticulate thin film were confirmed by the morphological, structural and optical studies of electrophoretically deposited PANI/TIO2 nanoparticulate thin film. The increased size of TiO2 nanoparticles indicated the well penetration of PANI molecules into the pores of mesoporous TiO2 nanoparticulate thin film. The XPS studies of PANI/TiO2 heterostructure exhibited the surface bonding and interaction between PANI molecules and TiO2 nanoparticles. The current-voltage (I-V) characterization of PANI/TiO2 heterostructure was carried out in the forward and the reverse bias at the applied voltage ranges from -1 V to +1 V with a scan rate of 2 mV/s. The constructed Pt/PANI/TiO2 heterostructure device established diodic behavior with non-linear nature of I-V curves.

14.
J Nanosci Nanotechnol ; 11(4): 3306-13, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21776701

RESUMO

A heterostructure was fabricated using p-type plasma polymerized polyaniline (PANI) and n-type (single and bilayer) titanium dioxide (TiO2) thin film on FTO glass. The deposition of single and bilayer TiO2 thin film on FTO substrate was achieved through doctor blade followed by dip coating technique before subjected to plasma enhanced polymerization. To fabricate p-n heterostructure, a plasma polymerization of aniline was conducted using RF plasma at 13.5 MHz and at the power of 120 W on the single and bilayer TiO2 thin film electrodes. The morphological, optical and the structural characterizations revealed the formation of p-n heterostructures between PANI and TiO2 thin film. The PANI/bilayer TiO2 heterostructure showed the improved current-voltage (I-V) characteristics due to the substantial deposition of PANI molecules into the bilayer TiO2 thin film which provided good conducting pathway and reduced the degree of excitons recombination. The change of linear I-V behavior of PANI/TiO2 heterostructure to non linear behavior with top Pt contact layer confirmed the formation of Schottky contact at the interfaces of Pt layer and PANI/TiO2 thin film layers.


Assuntos
Compostos de Anilina/química , Eletrodos , Membranas Artificiais , Nanoestruturas/química , Nanoestruturas/ultraestrutura , Semicondutores , Titânio/química , Condutividade Elétrica , Desenho de Equipamento , Análise de Falha de Equipamento , Gases em Plasma/química
15.
J Nanosci Nanotechnol ; 11(7): 5934-8, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22121634

RESUMO

The work reports the synthesis, characterization, and the properties of high-purity silica nanospheres from low-cost rice husk. Primarily, the rice husk was washed with distilled water (DW) and subjected to acid leaching to remove the impurities. The treated rice husk was annealed at different temperatures (620 and 900 degrees C) for varied time periods to achive the desirable silica nanospheres. The annealing temperature and time considerably affected the properties of the synthesized silica nanospheres. The morphology studies confirmed that the size of nanospheres were of approximately 50-60 nm. The photoluminesence studies revealed that the synthesized silica nanospheres showed less structural defects and good optical properties. On the basis of the formation and the characterization of silica nanospheres a possible mechanism was suggested. Inductively coupled plasma mass spectrometry (ICP-MS) analysis confirmed that the synthesized silica nanospheres contained approximately 99.93% purity.


Assuntos
Nanosferas/química , Nanotecnologia/métodos , Oryza/química , Dióxido de Silício/química , Temperatura Alta , Microscopia Eletrônica de Varredura , Análise Espectral , Difração de Raios X
16.
J Hazard Mater ; 404(Pt A): 124069, 2021 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-33059249

RESUMO

We demonstrate the hydrothermal synthesis of three dimension (3D) peony-like morphology of zinc gallate (ZnGa2O4), dominated by assembled nanosheets and applied as electrode material in electrochemical detection of N,N-dimethylmethanamide chemical. The crystalline, structural and compositional characterizations deduced the formation of high quality ZnGa2O4 with spinal crystal structure. Peony-like 3D ZnGa2O4 was benefited by a high surface area of ~62.3 m2 g-1, good pore distribution (mean pore diameter of ~23.3 nm) and large pore volume of ~0.3622 cm3 g-1. N,N-dimethylmethanamide chemical sensor based on peony-like 3D ZnGa2O4 electrode presented a linear curve in the working dynamic range of 1 nM-10 mM. Significantly improved chemical sensitivity of ~154.2 mA mM-1 cm-2 with low detection limit value of ~0.14 µM were achieved. The fabricated sensor based on peony-like 3D ZnGa2O4 electrode endorsed real sample analysis and ascertained the selectivity towards N,N-dimethylmethanamide chemical by analyzing a range of interfering analytes, viz. ethanol, tetrahydrofuran, methyl amine chemical.

17.
Nanoscale ; 9(44): 17544-17550, 2017 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-29111557

RESUMO

This work highlights the utilization of a novel hole-transporting material (HTM) derived from benzothiadiazole: 4-(3,5-bis(trifluoromethyl)phenyl)-7-(5'-hexyl-[2,2'-bithiophen]-5-yl)benzo[c][1,2,5]thiadiazole (CF-BTz-ThR) and aligned TiO2 nano-bundles (TiO2 NBs) as the electron transporting layer (ETL) for perovskite solar cells (PSCs). The aligned TiO2 NBs were grown on titanium (Ti)-coated FTO substrates using a facile hydrothermal method. The newly designed CF-BTz-ThR molecule with suitable highest occupied molecular orbital (HOMO) favored the effective hole injection from perovskite deposited aligned TiO2 NBs thin film. The PSCs demonstrated a power conversion efficiency (PCE) of ∼15.4% with a short circuit current density (Jsc) of ∼22.42 mA cm-2 and an open circuit voltage (Voc) of ∼1.02 V. The efficiency data show the importance of proper molecular engineering whilst highlighting the advantages of dopant-free HTMs in PSCs.

18.
J Colloid Interface Sci ; 472: 220-8, 2016 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-27038784

RESUMO

The leaf extract of Azadirachta indica (Neem) plant was utilized as reducing agent for the green synthesis of Mn3O4 nanoparticles (NPs). The crystalline analysis demonstrated the typical tetragonal hausmannite crystal structure of Mn3O4, which confirmed the formation of Mn3O4 NPs without the existence of other oxides. Green synthesized Mn3O4 NPs were applied for the catalytic thermal decomposition of ammonium perchlorate (AP) and as working electrode for fabricating the chemical sensor. The excellent catalytic effect for the thermal decomposition of AP was observed by decreasing the decomposition temperature by 175 °C with single decomposing step. The fabricated chemical sensor based on green synthesized Mn3O4 NPs displayed high, reliable and reproducible sensitivity of ∼569.2 µA mM(-1) cm(-2) with reasonable limit of detection (LOD) of ∼22.1 µM and the response time of ∼10 s toward the detection of 2-butanone chemical. A relatively good linearity in the ranging from ∼20 to 160 µM was detected for Mn3O4 NPs electrode based 2-butanone chemical sensor.


Assuntos
Azadirachta/química , Química Verde , Compostos de Manganês/química , Nanopartículas/química , Óxidos/química , Extratos Vegetais/química , Substâncias Redutoras/química , Butanonas/análise , Catálise , Técnicas Eletroquímicas , Temperatura Alta , Nanopartículas/ultraestrutura , Percloratos/química , Folhas de Planta/química , Compostos de Amônio Quaternário/química
19.
ChemSusChem ; 9(1): 10-27, 2016 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-26692567

RESUMO

The recent advances in perovskite solar cells (PSCs) created a tsunami effect in the photovoltaic community. PSCs are newfangled high-performance photovoltaic devices with low cost that are solution processable for large-scale energy production. The power conversion efficiency (PCE) of such devices experienced an unprecedented increase from 3.8 % to a certified value exceeding 20 %, demonstrating exceptional properties of perovskites as solar cell materials. A key advancement in perovskite solar cells, compared with dye-sensitized solar cells, occurred with the replacement of liquid electrolytes with solid-state hole-transporting materials (HTMs) such as 2,2',7,7'-tetrakis-(N,N-di-4-methoxyphenylamino)-9,9'-spirobifluorene (Spiro-OMeTAD), which contributed to enhanced PCE values and improved the cell stability. Following improvements in the perovskite crystallinity to produce a smooth, uniform morphology, the selective and efficient extraction of positive and negative charges in the device dictated the PCE of PSCs. In this Review, we focus mainly on the HTMs responsible for hole transport and extraction in PSCs, which is one of the essential components for efficient devices. Here, we describe the current state-of-the-art in molecular engineering of hole-transporting materials that are used in PSCs and highlight the requisites for market-viability of this technology. Finally, we include an outlook on molecular engineering of new functional HTMs for high efficiency PSCs.


Assuntos
Compostos de Cálcio/química , Fontes de Energia Elétrica , Óxidos/química , Energia Solar , Titânio/química , Modelos Teóricos , Fotoquímica , Propriedades de Superfície
20.
Anal Chim Acta ; 886: 165-74, 2015 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-26320649

RESUMO

Aligned p-type polypyrrole (PPy) nanofibers (NFs) thin film was grown on n-type silicon (100) substrate by an electrochemical technique to fabricate Schottky junction diode for the efficient detection of m-dihydroxybenzene chemical. The highly dense and well aligned PPy NFs with the average diameter (∼150-200 nm) were grown on n-type Si substrate. The formation of aligned PPy NFs was confirmed by elucidating the structural, compositional and the optical properties. The electrochemical behavior of the fabricated Pt/p-aligned PPy NFs/n-silicon Schottky junction diode was evaluated by cyclovoltametry (CV) and current (I)-voltage (V) measurements with the variation of m-dihydroxybenzene concentration in the phosphate buffer solution (PBS). The fabricated Pt/p-aligned PPy NFs/n-silicon Schottky junction diode exhibited the rectifying behavior of I-V curve with the addition of m-dihydroxybenzene chemical, while a weak rectifying I-V behavior was observed without m-dihydroxybenzene chemical. This non-linear I-V behavior suggested the formation of Schottky barrier at the interface of Pt layer and p-aligned PPy NFs/n-silicon thin film layer. By analyzing the I-V characteristics, the fabricated Pt/p-aligned PPy NFs/n-silicon Schottky junction diode displayed reasonably high sensitivity ∼23.67 µAmM(-1)cm(-2), good detection limit of ∼1.51 mM with correlation coefficient (R) of ∼0.9966 and short response time (10 s).

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