High Redox Research Articles

WO3-x nanorods/rGO/AgBiS2 Z-scheme heterojunction with comprehensive spectrum response and enhanced Fenton and photocatalytic activities

Tetracycline (TC) antibiotics and dyes are the prevalent water contaminants, and their removal from the water through photocatalysis is a plausible approach. However, most semiconductors in their pristine form need to be improved to be exploited in photocatalysis owing to poor photoresponse, intense carrier recombination, and inertness without irradiation. Herein, we demonstrate the modification of defective WO3-x by rGO and AgBiS2 in the form of WO3-x/rGO/AgBiS2 (R2). It exploits the superior conductivity and synergism of rGO to inhibit carrier recombination; thereby, Z-scheme heterojunction with AgBiS2 provides high redox potential. Defects in WO3-x enable electron (e-) storage in R2, which decomposes H2O2 to generate ROS without irradiation. Owing to these essences and broad-spectrum response, it removed 93.72, 82.77, and 84.82% of TC during photo-Fenton (PFR), night-Fenton (NFR), and photocatalytic (PCR) reactions, respectively. Its removal rates reached 94.74, 81.54, and 87.50% against rhodamine B (RhB) during PFR, NFR, and PCR, respectively. It is superior to memory catalysis (MC) and conventional Fenton reactions (CFR) because it can perform without and with irradiation across a broader pH range. So, this work is conducive to designing WO3-x-based catalysts to combat environmental and energy crises.

Energy harvesting from plants using hybrid microbial fuel cells; potential applications and future exploitation.

Microbial Fuel Cells (MFC) can be fuelled using biomass derived from dead plant material and can operate on plant produced chemicals such as sugars, carbohydrates, polysaccharides and cellulose, as well as being "fed" on a regular diet of primary biomass from plants or algae. An even closer relationship can exist if algae (e.g., prokaryotic microalgae or eukaryotic and unicellular algae) can colonise the open to air cathode chambers of MFCs driving photosynthesis, producing a high redox gradient due to the oxygenic phase of collective algal cells. The hybrid system is symbiotic; the conditions within the cathodic chamber favour the growth of microalgae whilst the increased redox and production of oxygen by the algae, favour a more powerful cathode giving a higher maximum voltage and power to the photo-microbial fuel cell, which can ultimately be harvested for a range of end-user applications. MFCs can utilise a wide range of plant derived materials including detritus, plant composts, rhizodeposits, root exudates, dead or dying macro- or microalgae, via Soil-based Microbial Fuel Cells, Sediment Microbial Fuel Cells, Plant-based microbial fuel cells, floating artificial islands and constructed artificial wetlands. This review provides a perspective on this aspect of the technology as yet another attribute of the benevolent Bioelectrochemical Systems.

Towards Durable and High-Rate Rechargeable Aluminum Dual-ion Batteries via a Crosslinked Diphenylphenazine-based Conjugated Polymer Cathode.

Rechargeable aluminum battery (RAB) is expected to be a promising energy storage technique for grid-scale energy storage. However, the development of RABs is seriously plagued by the lack of suitable cathode materials. Herein, we report two p-type conjugated polymers of L-PBPz and C-PBPz with the same building blocks of diphenylphenazine but different linkage patterns of linear and crosslinked structures as the cathode materials for Al dual-ion batteries. Compared to the linear polymer skeleton in L-PBPz, the crosslinked structure endows C-PBPz with amorphous nature and low dihedral angles of the polymer chains, which severally contribute to the fast diffusion of AlCl4 - with large size and the electron transfer during the redox reaction of diphenylphenazine. As a result, C-PBPz delivers a much better rate performance than L-PBPz. The crosslinked structure also leads to a stable cyclability with over 80000 cycles for C-PBPz. Benefiting from the fast kinetics, meanwhile, the C-PBPz cathode could realize a high redox activity of 117 mAh g-1, corresponding to an areal capacity of 2.30 mAh cm-2, even under a high mass loading of 19.7 mg cm-2 and a low content of 10 wt% conductive agent. These results might boost the development of polymer cathodes for RABs.

Screening Ultra-Stable (Phenazine)dioxyalkanocic Acids with Varied Water-Solubilizing Chain Lengths for High-Capacity Aqueous Redox Flow Batteries.

Aqueous redox flow batteries (ARFBs) hold great potential for large-scale energy storage. Recently, research on aqueous flow batteries has shifted toward water-soluble organic molecules with redox capabilities to reduce the use of mineral resources. The chemical and electrochemical stabilities of organic compounds are heavily influenced by their functional groups and reaction sites. In this study, we present a low-cost synthesis of the O-alkyl-carboxylate-functionalized derivatives of 2,3-dihydroxyphenazine, namely, phenazine-(2,3-diyl) dioxy dibutyric acid (DBEP) and phenazine-(2,3-diyl)dioxy diacetic acid (DAEP), which serve as negolytes and exhibit good reversibility and high redox kinetics. The evidence is provided to clarify the capacity degradation mechanisms of DAEP and DBEP by a series of comprehensive characterizations. Similar to anthraquinones functionalized with alkyl chains, the main degradation mechanism of DAEP modified with acetic acid is due to side chain loss. Longer side chains are more stable and can withstand long-term electrochemical reactions. DBEP modified with butyric acid exhibits superior chemical and electrochemical stability. Our results demonstrate that rational molecular design and suitable membranes, such as the alkaline ARFBs based on DBEP negolyte, potassium ferrocyanide (K4Fe(CN)6) posolyte, and custom sulfonated poly(ether ether ketone) membrane, can deliver a high open-circuit voltage of 1.17 V and high capacity retention of 99.997% per cycle for over 1000 cycles at 50 mA cm-2. This study highlights the importance of not only considering the modification position of the molecules but also focusing on the influence of various side chains on the redox core's stability toward sustainable grid-scale energy storage applications.

Energy Production in Microbial Fuel Cells (MFCs) during the Biological Treatment of Wastewater from Soilless Plant Cultivation

The management of drainage water (DW), which is produced during the soilless cultivation of plants, requires a high energy input. At the same time, DW is characterized by a high electrolytic conductivity, a high redox potential, and is also stable and putrefaction-free. In the present study, the natural properties of drainage water and a biotreatment method employing an external organic substrate in the form of citric acid (C/N 1.0, 1.5, 2.0) were utilized for energy recovery by a microbial fuel cell (MFC). The cathode chamber served as a retention tank for DW with a carbon felt electrode fixed inside. In turn, a biological reactor with biomass attached to the filling in the form of carbon felt served as the anode chamber. The filling also played the role of an electrode. The chambers were combined by an ion exchange membrane, forming an H letter-shaped system. They were then connected in an external electrical circuit with a resistance of 1k Ω. The use of a flow-through system eliminated steps involving aeration and mixing of the chambers’ contents. Citric acid was found to be an efficient organic substrate. The voltage of the electric current increased from 44.34 ± 60.92 mV to 566.06 ± 2.47 mV for the organic substrate dose expressed by the C/N ratio ranging from 1.0 to 2.0. At the same time, the denitrification efficiency ranged from 51.47 ± 9.84 to 95.60 ± 1.99% and that of dephosphatation from 88.97 ± 2.41 to 90.48 ± 1.99% at C/N from 1.0 to 2.0. The conducted studies confirmed the possibility of recovering energy during the biological purification of drainage water in a biofilm reactor. The adopted solution only required the connection of electrodes and tanks with an ion-selective membrane. Further research should aim to biologically treat DW followed by identification of the feasibility of energy recovery by means of MFC.

Construction of B doped g-C3N4/Ni-MOF-74 porous heterojunction with boosted carrier separation for photocatalytic H2 generation

Novel heterojunction is favored to improve the separation of photogenerated carriers and maintain high redox ability. A porous heterojunction combining porous metal-organic frameworks (MOF), Ni-MOF-74, and porous B-doped g-C3N4 (BCN) was fabricated for solar-light-driven H2 generation. The permeable surface and type-I carrier transfer mode not only created more reactive sites for H2 generation but also facilitated mass transfer at the contact interphase among BCN and Ni-MOF-74 due to a slight difference in their valence bond energy, which enhanced the excellent light trapping ability and expanded spectral absorbance range and thus solving the intrinsic drawback of fast charge recombination of pristine g-C3N4. Besides that, B-doping enhanced redox ability and transport separation, and the BCN/Ni-MOF-74 composite demonstrated dramatically reduced hydrogen production overpotential. The optimal BCN-NM-3 showed outstanding H2 generation up to 2190 μmol g−1h−1, almost 11 times higher than BCN. The current study will benefit the development of new MOF-based photocatalysts and be influential in meeting environmental demands in the future.

Interior-Confined Vacancy in Potassium Manganese Hexacyanoferrate for Ultra-Stable Potassium-Ion Batteries.

Metal hexacyanoferrates (HCFs) are viewed as promising cathode materials for potassium-ion batteries (PIBs) because of their high theoretical capacities and redox potentials. However, the development of an HCF cathode with high cycling stability and voltage retention is still impeded by the unavoidable Fe(CN)6 vacancies (VFeCN) and H2O in the materials. Here, a repair method is proposed that significantly reduces the VFeCN content in potassium manganese hexacyanoferrate (KMHCF) enabled by the reducibility of sodium citrate and removal of ligand H2O at high temperature (KMHCF-H). The KMHCF-H obtained at 90 °C contains only 2% VFeCN, and the VFeCN is concentrated in the lattice interior. Such an integrated Fe-CN-Mn surface structure of the KMHCF-H cathode with repaired surface VFeCN allows preferential decomposition of potassium bis(fluorosulfonyl)imide (KFSI) in the electrolyte, which constitutes a dense anion-dominated cathode electrolyte interphase (CEI) , inhibiting effectively Mn dissolution into the electrolyte. Consequently, the KMHCF-H cathode exhibits excellent cycling performance for both half-cell (95.2 % at 0.2 Ag-1 after 2000 cycles) and full-cell (99.4 % at 0.1 Ag-1 after 200 cycles). This thermal repair method enables scalable preparation of KMHCF with a low content of vacancies, holding substantial promise for practical applications of PIBs.

Rational construction Ag/LiF/sulfide rich protective layer for remarkably enhancing the stability of Li metal anodes

Li metal is a promising anode material for high-energy–density batteries due to its high theoretical capacity and low redox potential. However, both the uncontrolled Li dendrite growth and unstable solid electrolyte interphase (SEI) layer restricts its large-scale practical applications. Herein, an artificial protective layer consisting of Ag nanoparticles, lithium fluoride (LiF) and sulfide are innovatively designed and fabricated via the in-situ chemical reaction between Ag(I) trifluoromethylthiolate (AgSCF3) and Li metal. Density functional theory (DFT) results indicate that Ag nanoparticles have a high binding energy with Li atom and LiF/sulfide have wide band gap, which would provide plenty of nucleation sites for Li+ and reduce the direct contact between inner Li metal and the electrolyte. The co-existence of Ag and LiF/sulfide results in a strong synergistic effect, and this is confirmed by the systematical comparison with single modified Ag-Li and double modified F/S-Li anodes. Benefitting from this synergistic effect, the Ag/F/S-Li symmetrical cells can stably work for 2000 h with low-voltage hysteresis at current density of 1 mA cm−2. Full cells assembled with LiCoO2 (LCO) and LiFePO4 (LFP) cathodes displays much better long‐term cycle performance when the Ag/F/S-Li anode is applied. Furthermore, this Ag/F/S-Li modification can significantly enhance discharge capacity, rate performance, as well as energy density of Li(or LiB alloy)||MnO2 primary cells. This promising work promotes the practical application of Li metal and provides new insight into the protective layer design in stable Li metal batteries.

Breaking the Symmetry of Nitrogen‐Coordinated Single‐Atom Catalysts for Advanced Peroxymonosulfate Oxidation

AbstractTuning the electronic distribution of the single‐atom sites in single‐atom catalysts (SACs) is crucial for unlocking their catalytic potential. The four‐nitrogen‐coordinated transitional metal (M−N4) configuration has been widely investigated in peroxymonosulfate (PMS)‐based advanced oxidation processes (PMS‐AOPs), but restricted by the sluggish electron transfer from PMS to generate the high‐valent metal‐oxo (HVMO), reactive species with high redox potentials and long half‐lives, for the degradation of organic pollutants in water due to its symmetric structure. Recently, the SACs with asymmetric coordination configurations are found to break the symmetric electronic distribution of M−N4, which facilitates the O−H and O−O bond breaking in PMS, thus promoting HVMO formation. Asymmetric coordination has emerged as a novel and effective strategy for single‐atom coordination modulation. In this paper, two strategies for breaking the symmetry of nitrogen‐coordinated SACs by planar heteroatom doping and axial optimization engineering are outlined, and the reaction mechanisms on the formation of HVMO species over asymmetrically coordinated SACs via PMS activation are highlighted. Finally, we prospect the development of asymmetrically coordinated SACs in water purification.

Visible-light-response 2D/2D Bi2Fe4O9/ZnIn2S4 van der Waals S-scheme heterojunction with efficient photocatalysis-self-Fenton degradation of antibiotics

Constructing a high-efficient self-sufficient photo-Fenton system for pollutant degradation without the need for additional hydrogen peroxide (H2O2) remains a significant challenge. Herein, a photocatalysis-self-Fenton system based on 2D/2D Bi2Fe4O9/ZnIn2S4 (BFO/ZIS) van der Waals S-scheme heterojunction was successfully constructed for efficient degradation of antibiotic contaminants. The optimal BFO/ZIS-3 % sample achieves an impressive tetracycline (TC) degradation rate (88.8 %, 50 mg/L) after 120 min visible light irradiation, and the apparent rate constant (kapp) for BFO/ZIS photocatalysis-self-Fenton system is 14.107 times higher than the Fenton system and 2.866 times higher than the photo-Fenton system, respectively. A series of characterization tests revealed the construction of a 2D/2D BFO/ZIS van der Waals S-scheme heterojunction, not only could create a larger interface area for providing the active sites, but also form the internal electric field for enhancing photo-generated carrier separation and migration efficiency, retaining a substantial number of photo-generated charges with high redox potentials and promoting the progression of photocatalysis-self-Fenton reactions and the conversion of Fe3+/Fe2+. This strategy presents a new avenue for developing high-efficient photocatalysis-self-Fenton system.

Understanding a Core Pilin of the Type IVa Pili of Acidithiobacillus thiooxidans, PilV.

Pilins are protein subunits of pili. The pilins of type IV pili (T4P) in pathogenic bacteria are well characterized, but anything is known about the T4P proteins in acidophilic chemolithoautotrophic microorganisms such as the genus Acidithiobacillus. The interest in T4P of A. thiooxidans is because of their possible role in cell recruitment and bacterial aggregation on the surface of minerals during biooxidation of sulfide minerals. In this study we present a successful ad hoc methodology for the heterologous expression and purification of extracellular proteins such as the minor pilin PilV of the T4P of A. thiooxidans, a pilin exposed to extreme conditions of acidity and high oxidation-reduction potentials, and that interact with metal sulfides in an environment rich in dissolved minerals. Once obtained, the model structure of A. thiooxidans PilV revealed the core basic architecture of T4P pilins. Because of the acidophilic condition, we carried out in silico characterization of the protonation status of acidic and basic residues of PilV in order to calculate the ionization state at specific pH values and evaluated their pH stability. Further biophysical characterization was done using UV-visible and fluorescence spectroscopy and the results showed that PilV remains soluble and stable even after exposure to significant changes of pH. PilV has a unique amino acid composition that exhibits acid stability, with significant biotechnology implications such as biooxidation of sulfide minerals. The biophysics profiles of PilV open new paradigms about resilient proteins and stimulate the study of other pilins from extremophiles.

Rational nanoarchitectonics of polypyrrole/graphene/polyimide composite fibrous membranes with enhanced electrochemical performance as self-supporting flexible electrodes for supercapacitors

Constructing self-supporting electrodes with the combination of excellent flexibility and superior electrochemical properties is essential to the development of high-performance supercapacitors for flexible electronics and wearable devices. Herein, a highly flexible polypyrrole/reduced graphene oxide/modified-polyimide composite fibrous membranes (PPy/RGO/M-PI CFMs) are prepared via electrostatic self-assembly of reduced graphene oxide (RGO) and in-situ deposition of polypyrrole onto SnCl2-modified polyimide electrospun fibrous membranes (M-PI FMs). M-PI FMs ensure rich pore structure and remarkable flexible properties, the electronic conductivity of the sample is greatly promoted by RGO, and polypyrrole (PPy) provide the capability of high redox pseudo capacitive charge storage for the electrode. Benefiting from the compact assembly of RGO and the uniform deposition of polypyrrole on the fiber surface of the M-PI FMs, the synthesized PPy/RGO/M-PI CFMs have a remarkable area capacitance of 1437.1 mF cm−2, a long cycle life of 84.9 % retention over 5000 cycles, and outstanding mechanical stability. And the assembled symmetric supercapacitor with PPy/RGO/M-PI CFMs deliver an exceptional area capacitance of 363.1 mF cm−2, superior energy density of 32.3 μWh cm−2 and 77.6 % capacitance retention after 5000 cycles. Therefore, this flexible and free-standing PPy/RGO/M-PI CFMs can be regarded as a promising candidate for flexible supercapacitor electrodes.

Indolocarbazole‐Based Small Molecule Cathode‐Active Material Exhibiting Double Redox for High‐Voltage Li‐Organic Batteries

Most organic electrode materials (OEMs) for rechargeable batteries employ n‐type redox centers, whose redox potentials are intrinsically limited <3.0 V versus Li+/Li. However, p‐type materials possessing high redox potentials experience low specific capacities because they are capable of only a single redox reaction within the stable electrochemical window of typical electrolytes. Herein, we report 5,11‐diethyl‐5,11‐dihydroindolo[3,2‐b]carbazole (DEICZ) as a novel p‐type OEM, exhibiting stable plateaus at high discharge potentials of 3.44 and 4.09 V versus Li+/Li. Notably, the second redox potential of DEICZ is within the stable electrochemical window. The mechanism of the double redox reaction is investigated using both theoretical calculations and experimental measurements, including density functional theory calculations, ex situ electron spin resonance, and X‐ray photoelectron spectroscopy. Finally, hybridization with single‐walled carbon nanotubes (SWCNT) improves the cycle stability and rate performance of DEICZ owing to the π–π interactions between the SWCNT and co‐planar molecular structure of DEICZ, preventing the dissolution of active materials into the electrolyte. The DEICZ/SWCNT composite electrode maintains 70.4% of its initial specific capacity at 1‐C rate and also exhibits high‐rate capability, even performing well at 100‐C rate. Furthermore, we demonstrate its potential for flexible batteries after applying 1000 bending stresses to the composite electrode.

Constructing oxygen defect-rich Bi2WO6/CeO2 S-scheme heterojunction for boosted photocatalytic antibiotic removal

Efficient photocatalytic eradication of antibiotic contaminant from water is of significance for the sustainability of the aquatic environment. Oxygen defective Bi2WO6/CeO2 S-scheme heterojunctions were obtained by two-step hydrothermal processes. The optimal Bi2WO6/CeO2 heterostructure (BC-10) delivered degradation efficiencies of 86.6 % and 87.1 % for tetracycline (TC) and ciprofloxacin (CIP), respectively. The boosted photocatalytic performance of BC-10 was attributed to the increased specific surface area, S-scheme construction and the formed oxygen-defect energy level which promoted the fast charge transfer and separation of photoinduced h+/e– pairs. In addition, experiments confirmed that BC-10 possessed a good catalytic performance for other organic pollutants. The toxic behavior of the TC-removal solution was verified via the Ecological Structure-Activity Relationship (ECOSAR) model and hemp-pea growth experiment, and the possible photocatalytic degradation mechanism of TC and CIP on BC-10 was proposed. This work offers an applicable construction concept of advanced photocatalysts with high redox capacity for wastewater remediation.

Modelling the redox imbalance and oxidative stress in the hippocampus at aluminum neurotoxicity and initiating the coenzyme А biosynthesis

An Alzheimer-like pathological process was induced in mature female Wistar CRL: (WI) WUBR rats using aluminum chloride (200 mg/kg, intragastrically, 6 weeks) in order to model redox imbalance and oxidative stress (OS) in the hippocampus and study the possibilities of their correction 2 weekly administration of coenzyme A biosynthesis modulators (panthenol – PL, pantethine – PT, homopantothenate – HP) at a dose of 200 mg/kg intragastrically for 2 weeks). Against the background of activation of peroxidation processes and a decrease in acetylcholinesterase activity, a decrease in the reduction potential of glutathione and the level of the acid-soluble fraction of CoA was observed with a simultaneous increase in the activity of glutathione-metabolizing enzymes (GR, GPx, GST), the process of S-glutathionylation of proteins and the level of protein thiols. The consumption of the precursors of CoA biosynthesis in full (PL, PT) or in part (HP) had an antioxidant effect, restored the activity of AChE, the level and reduction potential of glutathione and glutathione-metabolizing enzymes, the process of S-glutathionylation, and stimulated the activity of enzymes generating NADPH+. Taking into account the low modulating effect of coenzyme precursors on the level of CoA in the hippocampus and their high redox pharmacological activity, their non-coenzymatic effect on redox mechanisms leading to an increase in the bioavailability of reducing equivalents and energy status is assumed.

Washable and anti-impact conductive cellulose yarn-based energy meta-textile against harsh environments

Flexible fiber-based zinc-ion batteries are highly regarded as potential for wearable electronic devices due to their high theoretical capacity and low redox potential. However, currently reported energy storage devices have limited practicality due to their inability to operate underwater or withstand mechanical stress. In this study, we present a multifunctional flexible fiber-based zinc-ion battery with exceptional durability, exhibiting high hammering resistance (maintaining 89.66 % capacity after 30 hammering cycles) and washing resistance (maintaining 77.97 % capacity after 30 min of washing). Moreover, the battery shows promising electrochemical performance, with a specific capacity 43.53 mAh g–1 and an energy density of 51.94 mWh g–1. Assembling and weaving multiple batteries into an energy meta-textile allows for normal mobile phone charging underwater and stable charge retention during mechanical stress, demonstrating potential for application in harsh environments.

The visible optical driving N-S co-doped La2Ti2O7 activated peroxydisulfate for carbamazepine removal: Mechanism and performance

Carbamazepine (CBZ) as an “emerging pollutant”, which poses a threat to human health. Photocatalytic activation of peroxydisulfate (PDS)-based advanced oxidation processes (AOPs) can deep oxidation of CBZ pollutants through the generation of free radicals with high redox potential. However, most of common photocatalysts only have a narrow band gap, which limits their application under visible light. In order to broaden the band gap of photocatalysis, herein we report the N-S co-doping in La2Ti2O7 (N-S LTO) is viable, and then evaluate the visible light activation of PDS to remove the pollutants of CBZ. Compared with pure LTO and N or S mono-doped LTO, the degradation efficiency of CBZ in N-S LTO/PDS/Vis system was 2.18, 1.45, and 1.41 times improved, respectively, under the visible light irradiation condition. Furthermore, the mechanism of CBZ degradation under N-S LTO/PDS/Vis processes was explored and revealed that the HO• and SO4•− were the main substances for the breakage of CBZ molecules. The further physicochemical characterization of samples convinced the active sites in N-S LTO for PDS motivation and oxidation processes with the best separation and migration ability of carriers than other samples. Finally, combined with density functional theory (DFT) calculations, the detailed degradation pathways of CBZ were proposed. This work not only provides insight into the construction of photocatalysts with co-doping for PDS activation, but also brings an inspiration of CBZ degradation in water treatment.

Enhanced efficiency of refractory organic pollutant degradation over a wide pH range by peroxymonosulfate activated by cobalt-doped FeS

A series of cobalt-doped FeS (x% Co–FeS) nanoparticles, prepared via a hydrothermal method, were introduced as catalysts for generating radicals from peroxymonosulfate (PMS) to degrade the endocrine disrupter bisphenol S (BPS) in wastewater. The kinetic results revealed that only a small amount of Co doping (7% At.) could greatly improve the efficiency of PMS activation by FeS, leading to the rapid degradation of BPS (0.21min−1 vs. 0.0046 min−1), and no secondary pollution caused by Co leaching. Notably, exceptional activation was observed over a wide pH range from 4 to 11. Moreover, various background ions (NO3−, Cl−, CO32−) and temperatures (10.0–55.0 °C) minimally affected BPS degradation, suggesting excellent applicability in different sewage environments. Furthermore, quenching experiments, coupled with electron paramagnetic resonance technology, identified singlet oxygen (1O2) and sulfate radicals (SO4•-) as the primary reactive oxygen species responsible for BPS degradation. Due to the selectivity of 1O2 and the high redox potential of SO4•-, this technology had excellent anti-interference and degradation ability. In six repeated batch experiments, the catalysts showed favorable cyclability and stability due to Co(II)/Co(III) cycling mediated by structural S2−. These results provided insights into the potential applications of modifying natural FeS-type minerals as a promising heterogeneous catalyst for environmental restoration.

Exploring innovative synthetic solutions for advanced polymer-based electrochromic energy storage devices: Phenoxazine as a promising chromophore

The current investigation offers an innovative synthetic solution regarding electrochromic (EC) and energy storage applications by exploring phenoxazine (POZ) moiety. Subsequently, three POZ-based polymers (polyimide, polyazomethine, and polyamide) were synthesized to ascertain the superior performer. The polyamide exhibited remarkable attributes, including high redox stability during 500 repetitive CVs, optical contrast of 61.98%, rapid response times of 1.02 and 1.38 s for coloring and bleaching, EC efficiency of 280 cm2 C−1, and decays of the optical density and EC efficiency of only 12.18% and 6.23% after 1000 cycles. Then, the energy storage performance of polyamide PA was tested, for which the following parameters were obtained: 74.7 F g−1 (CV, scan rate of 10 mV s−1) and 118 F g−1 (GCD, charging current of 0.1 A g−1). Then, the polyamide was tested in EES devices, which yielded the following EC parameters: an optical contrast of 62.15%, response times of 9.24 and 5.01 s for coloring and bleaching, EC efficiency of 178 cm2 C−1, and moderate decays of 20.25% and 23.24% for the optical density and EC efficiency after 500 cycles. The energy storage performance included a capacitance of 106 F g−1 (CV, scan rate of 0.1 mV s−1) and 9.23 F g−1 (GCD, charging current of 0.1 A g−1), capacitance decay of 11.9% after 500 cycles, and 1.7 V retention after 2 h. Also, two EES devices connected in series powered a 3 V LED for almost 30 s.

Porous spherical indium oxide-loaded BiOIO3 nanosheets to construct Z-scheme heterojunction to enhance photocatalytic activity

In this work, In2O3/BiOIO3 Z-scheme heterojunction composites enriched with oxygen vacancies were prepared by hydrothermal and calcination methods. Combining the experimental results with DFT calculations, it is found that the photogenerated electrons of In2O3-loaded BiOIO3 are transferred along the Z-scheme path, which proves that the In2O3/BiOIO3 Z-scheme heterojunction is successfully synthesized. The introduction of In2O3 has resulted in abundant oxygen vacancies on the surface of the composites. Oxygen vacancies construct new carrier transfer channels to accelerate the separation and transfer efficiency of electron-hole pairs. The photocatalytic activity was evaluated by the removal efficiency of the heavy metal mercury in the gas phase. The best sample had a Hg removal efficiency of 98.5 %. Finally, we propose that the synergistic interaction of oxygen vacancies and Z-scheme heterojunction promotes the activation of molecular oxygen and the generation of more ROS (·O2- and·OH) with high redox reactivity and analyze the mechanism in detail.