Textile industry consumes a large proportion of available water and releases huge amounts of toxic azo dye effluents, leading to an inevitable situation of acute environmental pollution that has been ...a significant threat to mankind. Decolorization or detoxification of harmful azo dyes has become a global priority to overcome the disastrous consequences and salvage the ecosystem. Biodegradation of textile azo dyes by endophytes stands to be a lucrative and viable alternative over conventional physico-chemical methods, owing to their eco-friendliness, cost-competitive and non-toxic nature. Especially, plant endophytic microbes exhibit promising biodegradation potential which has wired up the effective removal of textile azo dyes, attributing to their ability to produce dye degrading enzymes, laccases, peroxidases and azoreductases. Although both bacterial and fungal endophytes have been tried for azo dye degradation, endophytic fungi find broader application over bacteria. Despite of the advancements made in microbe-mediated biodegradation, there is still a need to fill the gap in lab to in situ translation of biodegradation research. This review concisely accentuates the xenobiotics of textile azo dyes and microbial mechanisms of biodegradation of textile azo dyes, positing plant endophytic community, especially bacterial and fungal endophytes as the potential dye degraders, highlighting currently reported dye degrading endophytic species.
Herein, we report the synthesis of between SnO
2
QDs /AgVO
3
nanoribbons/g-C
3
N
4
nanosheets of ternary photocatalytic systems for the production of H
2
through light irradiation. The SnO
2
/AgVO
3
.../g-C
3
N
4
photocatalyst was successfully produced by using the hydrothermal process. The structural characterizations of the samples revealed the successful formation of ternary heterostructures where SnO
2
, AgVO
3
and g-C
3
N
4
(quantum dots/nanoribbons/nanosheets) 0D/1D/2D structures make a good interface with each other. The fabricated heterostructures of AgVO
3
/g-C
3
N
4
and SnO
2
/AgVO
3
/g-C
3
N
4
photocatalytic structures performed enriched photocatalytic performance for H
2
production over that of the pristine g-C
3
N
4
, AgVO
3
and SnO
2
photocatalysts. The AgVO
3
/g-C
3
N
4
and SnO
2
/AgVO
3
/g-C
3
N
4
of photocatalysts were found to produce H
2
of around 17,000 μmol g
-1
and 77,000 μmol g
-1
, respectively, which is much 4.5 times greater than that of AgVO
3
/g-C
3
N
4
photocatalyst. Moreover, the photodegradation behaviours of prepared catalysts were studied with the dye (rhodamine B, RhB) under light irradiation. The ternary composite SnO
2
/AgVO
3
/g-C
3
N
4
performed photodegradation of RhB in 50 min. The higher photocatalytic activity for the ternary photocatalysts is predominantly due to the effective charge separation at the perfect interface formation amid SnO
2
and AgVO
3
/g-C
3
N
4
.
Herein, we report the design and synthesis strategy of a new class of five EDOT based co-sensitizers (CSGR1-5) by introducing different donors (2,3,4-trimethoxypheny, 2,4-dibutoxyphenyl, and ...2,4-difluorophenyl) and anchoring groups (rhodamine-3-acetic acid and cyanoacetic acid) systematically. The synthesized metal-free organic co-sensitizers were employed for cocktail dye-sensitized solar cells along with N749 (black dye). The DSSC devices with a mixture of co-sensitizers (CSGR1-5) and N749 have shown a 7.95%, 8.40%, 7.81%, 6.56% and 6.99% power conversion efficiency (PCE) respectively, which was more than that of single N749 dye PCE (6.18%). Enhanced efficiency could be ascribed to the increased short circuit current (
) and open circuit voltage (
). The increased
was achieved due to enhanced light harvesting nature of N749 device upon co-sensitization with CSGR dyes and feasible energy levels of both the dyes. The
was improved due to better surface coverage which helps in decreasing the rate of recombination. The detailed optical and electrochemical properties were investigated and complimented with theoretical studies (DFT).
Exposing catalytically active metal sites in metal–organic frameworks (MOFs) while maintaining porosity is beneficial for increasing electron transport to achieve better electrochemical energy ...conversion performance. Herein, we propose an in situ method for MOF formation and loading onto TiO2 nanorods (NR) using a simple solution-processable method followed by annealing to obtain TiO2-Co3O4. The as-prepared TiO2-ZIF-67 based photoanodes were annealed at 350, 450, and 550 °C to study the effect of carbonization on photo-electrochemical water oxidation. The successful loading of ZIF-67 on TiO2 and the formation of TiO2-Co3O4 heterojunction were confirmed by XRD, XPS, FE-SEM, and HRTEM analyses. TiO2-Co3O4-450 (the sample annealed at 450 °C) showed an enhanced photocurrent of 2.4 mA/cm2, which was 2.6 times larger than that of pristine TiO2. The improved photocurrent might be ascribed to the prepared p–n heterostructures (Co3O4 and TiO2), which promote electron–hole separation and charge transfer within the system and improve the photoelectrochemical performance. Moreover, the preparation of Co3O4 from the MOF carbonization process improved the electrical conductivity and significantly increased the number of exposed active sites and enhanced the photoresponse performance. The as-prepared ZIF-67 derived TiO2-Co3O4 based photoanodes demonstrate high PEC water oxidation, and the controlled carbonization method paves the way toward the synthesis of low-cost and efficient electrocatalysts.
Supercapacitors have become a popular form of energy-storage device in the current energy and environmental landscape, and their performance is heavily reliant on the electrode materials used. ...Carbon-based electrodes are highly desirable due to their low cost and their abundance in various forms, as well as their ability to easily alter conductivity and surface area. Many studies have been conducted to enhance the performance of carbon-based supercapacitors by utilizing various carbon compounds, including pure carbon nanotubes and multistage carbon nanostructures as electrodes. These studies have examined the characteristics and potential applications of numerous pure carbon nanostructures and scrutinized the use of a wide variety of carbon nanomaterials, such as AC, CNTs, GR, CNCs, and others, to improve capacitance. Ultimately, this study provides a roadmap for producing high-quality supercapacitors using carbon-based electrodes.
Dye anchored counter electrode (DACE) based DSSC devices were successfully constructed using Y351-S and TP-DTP dyes and their photovoltaic performances were compared with the standard DSSCs. ...Increased IPCE and Jsc were observed for CO-DACE compared to the standard DSSCs, portraying the role of dye anchored counter electrode in enhancing the efficiency of CO-DACE.
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Partial absorption of the solar spectrum is one of the key limitations of dye-sensitized solar cells (DSSCs). In an attempt to address this issue, we have developed co-sensitized working electrode based dye anchored counter electrode (DACE) DSSC strategy to achieve panchromatic absorption using multiple dyes. Herein, we have synthesized a dithionopyrrole based TP–DTP dye and a porphyrin-based Y351-S dye and explored to a new type of DSSCs modified with DACE. To realize the effect of DACE electrode on the DSSC efficiency, we have fabricated five different DSSCs devices namely, S-DSSC1, S-DSSC2, S-DACE, CO-DSSC, and CO-DACE using these synthesized dyes and compared their performances systematically. In addition, the detailed impedance and stepped light-induced transient measurements of the photocurrent and voltage (SLIM-PCV) experiments are also performed to assess the charge transfer resistance and charge collection efficiency of these devices. The highest efficiency of 8.72±0.15% is observed for the CO-DACE-based devices, which is higher than the traditional DSSCs made of single dye-sensitized (S-DSSC1 and S-DSSC2), and co-sensitized DSSC (CO-DSSC). It can be attributed to the enhanced incident photon to current conversion efficiency (IPCE) and short circuit current (Jsc) which clearly portray the advantage of DACE electrode in harvesting maximum incident light.
Two new ullazine-based organic dyes have been synthesized for applications in nanocrystalline TiO2-based dye-sensitized solar cells (DSSCs). Overall conversion efficiencies up to 3.63% were obtained ...for DSSCs based on these dyes. The dye with a tert-butyl antenna exhibited a higher and redshifted absorption pattern resulting in increased light-harvesting property. Compared to the unsubstituted dye, the photocurrent density, open-circuit photovoltage and overall power conversion efficiency (PCE) of solar cells based on the tert-butyl substituted dye are improved. The decreased PCE of the solar cell based on unsubstituted dye results mainly from the increased recombination rate and decreased electron lifetime, as evidenced from impedance and photovoltage decay measurements. Density functional theory (DFT) and time-dependent DFT calculations were performed to predict the geometries, electronic structure, and the optical and electrochemical properties of the dyes.
Herein, we have successfully prepared self-doped carbon dots with nitrogen elements (NCD) in a simple one-pot hydrothermal carbonization method, using L-histidine as a new precursor. The effect of ...as-prepared carbon dots was studied for photoelectrochemical (PEC) water splitting by decorating NCDs upon TiO2 nanorods systematically by changing the loading time from 2 h to 8 h (TiO2@NCD2h, TiO2@NCD4h, TiO2@NCD6h, and TiO2@NCD8h). The successful decorating of NCDs on TiO2 was confirmed by FE-TEM and Raman spectroscopy. The TiO2@NCD4h has shown a photocurrent density of 2.51 mA.cm−2, 3.4 times higher than the pristine TiO2. Moreover, TiO2@NCD4h exhibited 12% higher applied bias photon-to-current efficiency (ABPE) than the pristine TiO2. The detailed IPCE, Mott–Schottky, and impedance (EIS) analyses have revealed the enhanced light harvesting property, free carrier concentration, charge separation, and transportation upon introduction of the NCDs on TiO2. The obtained results clearly portray the key role of NCDs in improving the PEC performance, providing a new insight into the development of highly competent TiO2 and NCDs based photoanodes for PEC water splitting.
A simple ruthenium(II) polypyridyl complex Ru(II)(dcbp)(L)(NCS)2 coded as MC219, where dcbp = 4,4′-dicarboxylic acid-2,2′-bipyridine, ...L = 4,4′-bis(3,5-di-tert-butyl-4-(hexyloxy)phenyl)-2,2′-bipyridine has been synthesized and fully characterized with IR, NMR, MS, UV–Vis and electrochemical measurements. The incident photon to current conversion efficiency of MC219 reached its highest 56% at 550 nm. Under standard Air Mass (AM) 1.5 sunlight, the sensitizer MC219 yielded a short-circuit photocurrent density (JSC) of 9.58 mA cm−2, an open-circuit voltage (VOC) of 0.655 V, and a fill factor (ff) of 0.733, corresponding to an overall conversion efficiency of 4.6% compared to that of standard N719 at 7.2% (JSC of 18.43 mA cm−2, VOC of 0.582 V, ff of 0.671).
•Bulky tert-butyl groups prevent aggregation and facilitate uniform monolayer.•Alkyl chains reduce the recombination rates.•MC219 showed better photo-voltage compared to standard N719.•MC219 showed good thermal stability compared to standard N719 and Z907.•Increased conjugation improved the molar extinction coefficient of the dye.
In this study, we designed mixed metal oxides with doping compound nano-constructions as efficient electrode materials for supercapacitors (SCs). We successfully prepared the Fe-dopant with NiCoOx ...grown on nickel foam (Fe-dopant@NiCoOx@NF) through a simple hydrothermal route with annealing procedures. This method provides an easy route for the preparation of high activity SCs for energy storage. Obtained results revealed that the Fe dopant has successfully assisted NiCoOx lattices. The electrochemical properties were investigated in a three-electrode configuration. As a composite electrode for SC characteristics, the Fe-dopant@NiCoOx@NF exhibits notable electrochemical performances with very high specific capacitances of 1965 F g−1 at the current density of 0.5 A g−1, and even higher at 1296 F g−1 and 30 A g−1, respectively, which indicate eminent and greater potential for SCs. Moreover, the Fe-dopant@NiCoOx@NF nanoneedle composite obtains outstanding cycling performances of 95.9% retention over 4500 long cycles. The improved SC activities of Fe-dopant@NiCoOx@NF nanoneedles might be ascribed to the synergistic reactions of the ternary mixed metals, Fe-dopant, and the ordered nanosheets grown on NF. Thus, the Fe-dopant@NiCoOx@NF nanoneedle composite with unique properties could lead to promising SC performance.
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