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The synthetic dyes and chemicals used in industries produce a tremendous amount of contaminated water. Most of the poisonous dyes generated from different textile industries are released directly to the environment. As a consequence, the discharge of wastewater from a large number of textile industries without prior treatment leads to significant negative impacts on human health. The utilization of efficient and inexpensive nano-adsorbent may reduce the adverse impacts of dyes in the environment due to their unique properties. To alleviate these issues, attention has been paid to develop efficient adsorbents for the removal of undesirable species from wastewater. Efficient and selective removal of dyes is gaining importance to reduce the environmental problems. Comparison of degradation efficiency for different catalysts could be a holistic approach that should be taken under consideration owing to search a suitable adsorbent. An in-depth evaluation of extensive variety of advanced adsorbents reported in literature for dye degradation has been furnished. In addition to underscoring the physico-chemical properties of different adsorbents, this review also endorses the mechanisms and efficiencies within the adsorption process. The challenges of dye degradation process are focused to reduce the adverse impacts of dyes in the environment. The critical assessment of next generation adsorbents would presumably be promoted the clean and affordable water purification process in practice.

Textile dye is one of the significant pollutants of water worldwide. However, dumping the textile effluent to the environment is a common in most of the developing countries. Contaminated water in the textile industry may contain various toxic ingredients and people were easily infected with various diseases. The contamination may affect the marine environment and consequently extends around the world. The recycling of waste water is the significant option to reduce the environmental pollution. In particular, adsorption approach is one of the significant strategies to treat dye-contaminated water due to their advantageous of physico-chemical properties. In this review paper, variety of potential adsorbents for dye removal were critically reviewed, focusing on the efficient adsorbent to remediate dye-contaminated water. Specifically, the recent development of adsorbents containing carbon, metal supported adsorbents, surface functionalized gel adsorbents and photo-adsorbents were reviewed focusing on cutting-edge processes. Comparison of degradation efficiency for different adsorbents, synthesis approaches and their physico-chemical properties were assessed in systematic way. The perspective of the adsorbent materials associated with the dye degradation was discussed thoroughly. The evaluation of different advanced materials would contribute to the development of the sustainable dye removal process in near future.

The synthetic dyes and chemicals used in industries produce a tremendous amount of contaminated water. Most of the poisonous dyes generated from different textile industries are released directly to the environment. As a consequence, the discharge of wastewater from a large number of textile industries without prior treatment leads to significant negative impacts on human health. The utilization of efficient and inexpensive nano-adsorbent may reduce the adverse impacts of dyes in the environment due to their unique properties. To alleviate these issues, attention has been paid to develop efficient adsorbents for the removal of undesirable species from wastewater. Efficient and selective removal of dyes is gaining importance to reduce the environmental problems. Comparison of degradation efficiency for different catalysts could be a holistic approach that should be taken under consideration owing to search a suitable adsorbent. An in-depth evaluation of extensive variety of advanced adsorbents reported in literature for dye degradation has been furnished. In addition to underscoring the physico-chemical properties of different adsorbents, this review also endorses the mechanisms and efficiencies within the adsorption process. The challenges of dye degradation process are focused to reduce the adverse impacts of dyes in the environment. The critical assessment of next generation adsorbents would presumably be promoted the clean and affordable water purification process in practice.

type:Journal Article, High quality perovskite film with high coverage and tight grain arrangement is critical for achieving high-efficiency and high-stability perovskite solar cells (PSCs). In this work, high quality perovskite films were successfully prepared by liquid nitrogen assisted method (LN method). Here, the vaporization of liquid nitrogen reduces the ambient temperature and absorb thermal energy from the substrate surface to accelerate the nucleation of perovskite. The results of scanning electron microscopy (SEM) shows that the perovskite films prepared by liquid nitrogen assisted method were dense and pinhole-free. The devices prepared by the LN method leads to a high-efficiency upto 16.53%, and the high efficiency device could maintain over 89% of the initial power conversion efficiency (PCE) even after 30 days storage in a desiccator at room temperature., source:https://doi.org/10.1021/acssuschemeng.8b05139

type:Journal Article, 01 August Compared with organic‐inorganic perovskites, all‐inorganic cesium‐based perovskites without volatile organic compounds have gained extensive interests because of the high thermal stability. However, they have a problem on phase transition from cubic phase (active for photo‐electric conversion) to orthorhombic phase (inactive for photo‐electric conversion) at room temperature, which has hindered further progress. Herein, novel inorganic CsPb1−xGexI2Br perovskites were prepared in humid ambient atmosphere without a glovebox. The phase stability of the all‐inorganic perovskite was effectively enhanced after germanium addition. In addition, the highest power conversion efficiency of 10.8 % with high open‐circuit voltage (VOC) of 1.27 V in a planar solar cell based on CsPb0.8Ge0.2I2Br perovskite was achieved. Furthermore, the highest VOC up to 1.34 V was obtained by CsPb0.7Ge0.3I2Br perovskite, which is a remarkable record in the field of all‐inorganic perovskite solar cells. More importantly, all the photovoltaic parameters of CsPb0.8Ge0.2I2Br perovskite solar cells showed nearly no decay after 7 h measurement in 50–60 % relative humidity without encapsulation., source:https://doi.org/10.1002/anie.201807270

type:Journal Article, Despite the high efficiency of MAPbI3 perovskite solar cells, the long term stability and degradation in humid atmosphere are issues that still needed to be addressed. In this work, magnesium iodide (MgI2) was first successfully used as a dopant into MAPbI3 perovskite prepared in humid air atmosphere. Mg doping decreased the valence band level, which was determined from photoelectron yield spectroscopy. Compared to the pristine MAPbI3 perovskite film, the 1.0% Mg-doped perovskite film showed increased crystal grain size and formation of pinhole-free perovskite film. Performance of the solar cell was increased from 14.2% of the doping-free solar cell to 17.8% of 1.0% Mg-doped device. Moreover, 90% of the original power conversion efficiency was still retained after storage in 30–40% relative humidity for 600 h., source:DOI:10.1021/acsami.8b06619

type:Journal Article, Despite the remarkable performance of organometallic halide perovskite solar cells (PSCs), their ultimate stability is still a major issue that inhibits the commercialization of this eminent technology. Herein, melamine hydroiodide (MLAI) is added to function methyl ammonium (CH3NH3+, MA+) lead iodide perovskite for fabricating structured perovskite with enhanced photovoltaic performance and stability in the harsh ambient atmosphere (35 °C, 60–70% relative humidity). Nearly no new phase formed even incorporated 25 mol.% MLAI induces the strain in the perovskite crystal structure. The MLAI‐structured perovskite film shows a denser and smoother surface than the pristine MAPbI3 perovskite. Planar PSCs based on 2 mol.% MLAI‐functionalized perovskite show 17.2% power conversion efficiency with nearly no hysteresis which is much higher than pristine MAPbI3 PSCs. Most importantly, the solar cell devices based on 2 mol.% MLAI‐functionalized perovskite still retain over 90% of the initial performance after being kept in ambient atmosphere for more than 560 h without encapsulation., source:https://doi.org/10.1002/solr.201800275

type:Journal Article, TiO2 is commonly used as an electron-transporting material in perovskite photovoltaic devices due to its advantages, including suitable band gap, good photoelectrochemical stability, and simple preparation process. However, there are many oxygen vacancies or defects on the surface of TiO2 and thus this affects the stability of TiO2-based perovskite solar cells under UV light. In this work, a thin (monolayer) SbI3 modification layer is introduced on the mesoporous TiO2 surface and the effect at the interface between of TiO2 and perovskite is monitored by using a quartz crystal microbalance system. We demonstrate that the SbI3-modified TiO2 electrodes exhibit superior electronic properties by reducing electronic trap states, enabling faster electron transport. This approach results in higher performances compared with electrodes without the SbI3 passivation layer. CH3NH3PbI3 perovskite solar cells with a maximum power conversion efficiency of 17.33% in air, accompanied by a reduction in hysteresis and enhancement of the device stability, are reported., source:DOI:10.1021/acsami.8b10062

type:Journal Article, Perovskite solar cells based on series of inorganic cesium lead bromide and iodide mixture, CsPbBr3-xI x , where x varies between 0, 0.1, 0.2, and 0.3 molar ratio were synthesized by two step-sequential deposition at ambient condition to design the variations of wide band gap light absorbers. A device with high overall photoconversion efficiency of 3.98 % was obtained when small amount of iodide (CsPbBr2.9I0.1) was used as the perovskite and spiro-OMeTAD as the hole transport material (HTM). We investigated the origin of variation in open circuit voltage, Voc which was shown to be mainly dependent on two factors, which are the band gap of the perovskite and the work function of the HTM. An increment in Voc was observed for the device with larger perovskite band gap, while keeping the electron and hole extraction contacts the same. Besides, the usage of bilayer P3HT/MoO3 with deeper HOMO level as HTM instead of spiro-OMeTAD, thus increased the Voc from 1.16 V to 1.3 V for CsPbBr3 solar cell, although the photocurrent is lowered due to charge extraction issues. The stability studies confirmed that the addition of small amount of iodide into the CsPbBr3 is necessarily to stabilize the cell performance over time.

Perovskite solar cells based on series of inorganic cesium lead bromide and iodide mixture, CsPbBr3-xI x , where x varies between 0, 0.1, 0.2, and 0.3 molar ratio were synthesized by two step-sequential deposition at ambient condition to design the variations of wide band gap light absorbers. A device with high overall photoconversion efficiency of 3.98 % was obtained when small amount of iodide (CsPbBr2.9I0.1) was used as the perovskite and spiro-OMeTAD as the hole transport material (HTM). We investigated the origin of variation in open circuit voltage, Voc which was shown to be mainly dependent on two factors, which are the band gap of the perovskite and the work function of the HTM. An increment in Voc was observed for the device with larger perovskite band gap, while keeping the electron and hole extraction contacts the same. Besides, the usage of bilayer P3HT/MoO3 with deeper HOMO level as HTM instead of spiro-OMeTAD, thus increased the Voc from 1.16 V to 1.3 V for CsPbBr3 solar cell, although the photocurrent is lowered due to charge extraction issues. The stability studies confirmed that the addition of small amount of iodide into the CsPbBr3 is necessarily to stabilize the cell performance over time.

The coupling of a solar cell with a super capacitor is gaining interest owing to its superior photo-to-electrical conversion efficiency and its in-situ energy storage ability for green and sustainable energy development. In this work, the electrochemical performances of the fabricated super capacitor and perovskite solar cell were individually measured for the fabrication of a photo-super capacitor. A Bi2O3/MnO2 based symmetrical and asymmetrical super capacitor were fabricated. The symmetrical super capacitor could charge up to 1.0 V, which gave a specific capacitance of 136.4 F/g at a scan rate of 2 mV/s. The power and energy densities of the bismuth-based symmetrical super capacitor were 51.8 W/kg and 7.1 Wh/kg, respectively and were improved to 25.6 Wh/kg and 115.3 W/kg when a Bi2O3/MnO2 positive electrode was integrated to a polypyrrole/reduced graphene oxide (PyR) negative electrode. It thus proven the feasibility of an asymmetrical super capacitor to promote the performance of a super capacitor. The dissatisfying stability performance of the Bi2O3/MnO2//PyR asymmetrical super capacitor (60% capacitance retained) prompted for screening of other pseudocapacitive materials. An asymmetrical super capacitor comprising a positive cobalt oxide/zinc oxide/reduced graphene oxide electrode (RZCo) and a negative polypyrrole/reduced graphene oxide electrode was then fabricated. A wide operational potential range for the RZCo//PyR asymmetrical super capacitor resulted in a high specific capacitance of 470.8 F/g, as opposed to the Bi2O3/MnO2 symmetrical super capacitor of 136.4 F/g and 144.1 F/g for the bismuth-based asymmetrical super capacitor, at a scan rate of 2mV/s, additionally exhibited 1.6-fold higher in energy and power densities, which fulfilling the criteria as the energy storage device for the photo-super capacitor.Perovskite solar cells were fabricated from a series of cesium based halide mixtures perovskite harvesting materials, denoted as CsPbBr3-xIx, where

A flexible supercapacitor comprising an electrolyte sandwiched between nickel foams electrodeposited with a nanocomposite. The nanocomposite comprises of a conducting polymer, graphene oxide and a metal oxide. Process of fabricating the flexible supercapacitor is also provided. The process comprises electrodepositing a nanocomposite electro-potentiostatically on a nickel foam from an aqueous solution comprising of a conducting monomer, graphene oxide and a metal salt, placed in one compartment cell followed by compressing an electrolyte between at least two layers of electrodeposited nickel foams.