Interrogating the Light-Induced Charging Mechanism in Li-Ion Batteries Using Operando Optical Microscopy

Photobatteries, batteries with a light-sensitive electrode, have recently been proposed as a way of simultaneously capturing and storing solar energy in a single device. Despite reports of photocharging with multiple different electrode materials, the overall mechanism of operation remains poorly understood. Here, we use operando optical reflection microscopy to investigate light-induced charging in LixV2O5 electrodes. We image the electrode, at the single-particle level, under three conditions: (a) with a closed circuit and light but no electronic power source (photocharging), (b) during galvanostatic cycling with light (photoenhanced), and (c) with heat but no light (thermal). We demonstrate that light can indeed drive lithiation changes in LixV2O5 while maintaining charge neutrality, possibly via a combination of faradaic and nonfaradaic effects taking place in individual particles. Our results provide an addition to the photobattery mechanistic model highlighting that both intercalation-based charging and lithium concentration polarization effects contribute to the increased photocharging capacity

Vanadium Dioxide Cathodes for High-Rate Photo-Rechargeable Zinc-Ion Batteries

Photovoltaics are an important source of renewable energy, but due the intermittent nature of insolation, solar cells usually need to be connected to rechargeable batteries, electrochemical capacitors or other energy storage devices, which adds to the complexity and cost of these systems. In this work, we report a cathode design for photo-rechargeable zinc-ion batteries (photo-ZIBs) that is inherently capable of harvesting sunlight to recharge without the need for external solar cells. The proposed photocathodes comprising a composite of vanadium dioxide nanorods and reduced graphene oxide, are engineered to provide the necessary charge separation and storage for photocharging under illumination. The photo-ZIBs achieve gravimetric capacities of ~ 282 mAh g-1 in the dark and ~ 315 mAh g-1 under illumination, at 200 mA g-1, demonstrating the use of light not only to charge the deceives, but additionally to enhance their capacity. The photo-ZIBs also demonstrate enhanced high-rate capabilities under illumination, as well as a capacity retention of ∼ 90% over 1000 cycles. The proposed photo-ZIBs demonstrate a promising new technology for addressing energy poverty, due to their high performance and inherent cost-efficiency and safety.Newton International Fellowship-Royal Society (UK) grant NIF∖R1∖181656 ERC Consolidator grant MIGHTY - 866005 EPSRC Graphene CDT EP/L016087/

Impact of physio-biochemical responses on amelioration of short-term storage and management of post-harvest seed quality of greengram (Vigna radiata)

The present study was carried out during winter (rabi) and rainy (kharif) seasons of 2021 and 2022 at Assam Agricultural University, Jorhat, Assam to address the significance of maintaining post-harvest seed quality and its management throughout the nation, and to promote the knowledge and create awareness among the farming communities and pulse growers at the national level in terms of the area with high rainfall and high relative humidity. The greengram [Vigna radiata (L.) R. Wilczek] variety (SGC-16) seeds were stored in 4 different types of packaging materials, viz. jute bag, polylined jute bags; HDPE (High Density Polyethylene) interwoven bags; and 700-gauze polythene bags and treated with treatment combination of emamectin benzoate (40 mg/kg) (chemical based); 5 ml/kg neem oil (plant based); 3 g/kg black pepper (recommended practise for the state); and 3 g/kg silica gel (desiccants). With an increase in storage time, a gradual decline in seed quality parameters such as viability, germination, seedling length, seedling dry weight, Seed vigour index-I, Seed vigour index-II, germination index value, field emergence, and chlorophyll content was observed. Variations for biochemical indicators of seed quality were also recorded. The seed germination above Indian Minimum Seed Certification Standard (IMSCS) level was maintained by all treatments up to 120 days of storage. However, emamectin benzoate (40 mg/kg) along with 3 g/kg of silica gel in HDPE interwoven bags found to be best in keeping seed quality standards with lowest lipid peroxidation activity (0.36 g/gm) and highest in seeds stored in jute bag (0.68 g/gm)

Zinc oxide ultraviolet photodetectors: rapid progress from conventional to self-powered photodetectors

This review article focuses on the current developments of UV photodetectors from conventional to self-powered device designs based on energy efficient ZnO nanomaterials.</p

Energy-Efficient Hydrogenated Zinc Oxide Nanoflakes for High-Performance Self-Powered Ultraviolet Photodetector

Light absorption efficiency and doping induced charge carrier density play a vital role in self-powered optoelectronic devices. Unique vanadium-doped zinc oxide nanoflake array (VZnO NFs) is fabricated for self-powered ultraviolet (UV) photodetection. The light harvesting efficiency drastically improved from 84% in ZnO NRs to 98% in VZnO NFs. Moreover, the hydrogenation of as-synthesized VZnO (H:VZnO) NFs displayed an outstanding increase in response current as compared to pristine structures. The H:VZnO NFs device presents an extraordinary photoelastic behavior with faster photodetection speed in the order of ms under a low UV illumination signal. Excellent responsivity and external quantum efficiency with larger value of specific detectivity of H:VZnO NFs device promises an outstanding sensitivity for UV signal and self-powered high-performance visible-blind photodetector

Effect of Magnetic Field on Photoresponse of Cobalt Integrated Zinc Oxide Nanorods

Cobalt integrated zinc oxide nanorod (Co-ZnO NR) array is presented as a novel heterostructure for ultraviolet (UV) photodetector (PD). Defect states in Co-ZnO NRs surface induces an enhancement in photocurrent as compared to pristine ZnO NRs PD. Presented Co-ZnO NRs PD is highly sensitive to external magnetic field that demonstrated 185.7% enhancement in response current. It is concluded that the opposite polarizations of electron and holes in the presence of external magnetic field contribute to effective separation of electron-hole pairs that have drifted upon UV illumination. Moreover, Co-ZnO NRs PD shows a faster photodetection speed (1.2 s response time and 7.4 s recovery time) as compared to the pristine ZnO NRs where the response and recovery times are observed as 38 and 195 s, respectively

Light Rechargeable Lithium-ion Batteries Using V2O5 Cathodes

Solar energy is one of the most actively pursued renewable energy sources, but like many other sustainable energy sources, its intermittent character means solar cells have to be connected to an energy storage system to balance production and demand. To improve the efficiency of this energy conversion and storage process, photo-batteries have recently been proposed where one of the battery electrodes is made from a photo-active material that can directly be charged by light without using solar cells. Here, we present photo-rechargeable lithium-ion batteries (Photo-LIBs) using photocathodes based on vanadium pentoxide nanofibers mixed with P3HT and rGO additives. These photocathodes support the photo-charge separation and transportation process needed to recharge. The proposed Photo-LIBs show capacity enhancements of more than 57% under illumination and can be charged to ~ 2.82 V using light and achieve conversion efficiencies of ~ 2.6% for 455 nm illumination and ~ 0.22% for 1 sun illumination

Synergistic effect in the heterostructure of ZnCo<inf>2</inf>O<inf>4</inf> and hydrogenated zinc oxide nanorods for high capacitive response

Herein, a novel heterostructure was fabricated by combining electrochemically and optically active materials to achieve a high capacitive response of 896 F g-1 at 5 A g-1. A network of ZnCo2O4 nanorods (NRs) was directly grown on a three-dimensional matrix of H:ZnO NRs (ZnCo2O4/H:ZnO NRs) that offered synergistic advantages by providing an optimum ion/charge transportation path, large electrochemically active surface area, and stable capacitive response during the electrolytic process. Furthermore, the fabricated solid-state asymmetric supercapacitor ZnCo2O4/H:ZnO NRs//activated carbon induced a large potential window of 1.5 V that offered excellent energy and power densities. In addition, optically active ZnCo2O4/H:ZnO NRs were also used for the conversion of optical energy over a broad wavelength range; thus, the as-fabricated asymmetric solid-state supercapacitor could easily provide the required power for the operation of a photodetector. Therefore, the unique heterostructure of ZnCo2O4/H:ZnO NRs not only presents excellent capacitive response but also demonstrates great potential for energy conversion

<span style="font-size:21.0pt;mso-bidi-font-size:14.0pt; line-height:115%;font-family:"Times New Roman","serif";mso-fareast-font-family: "Times New Roman";mso-ansi-language:EN-US;mso-fareast-language:EN-US; mso-bidi-language:AR-SA">Rhizoctonia wilt suppression of brinjal <i>(Solanum melongena </i>L) and plant growth activity by <i>Bacillus </i>BS2</span>

627-631<span style="font-size: 15.0pt;mso-bidi-font-size:8.0pt;font-family:" times="" new="" roman","serif""="">An antibiotic-producing and hydrogen-cyanide-producing rhizobacteria strain Bacillus BS2 showed a wide range of anti fungal activity against many Fusarium  sp. and brinjal wilt disease pathogen Rhizoctonia solani. Seed bacterization with the strain BS2 promoted seed germination and plant growth in leguminous plants Phaseolus vulgaris and non-leguminous <span style="font-size: 15.0pt;mso-bidi-font-size:8.0pt;font-family:" times="" new="" roman","serif""="">plants Solanum melongena <span style="font-size:21.0pt;mso-bidi-font-size:14.0pt; font-family:" times="" new="" roman","serif""="">L<span style="font-size:15.0pt; mso-bidi-font-size:8.0pt;font-family:" times="" new="" roman","serif""="">,  Brassica  oleracea var. capitata, B. oleraceae var. gongylodes and Lycopersicon  esculentum Mill in terms of relative growth rate, shoot height, root length , total biomass production and total chlorophyll content of leaves. Yield of bacterized plants were increased by 10 to 49% compared to uninoculated control plants. Brinjal sapling raised through seed bacterization by the strain BS2 showed a significantly reduced wilt syndrome of brinjal caused by Rhizoctonia solani . Control of wilt disease by the bacterium was due to the production of a ntibiotic-like substances, whereas plant growth -promotion was due to the activity of hydrogen cyanide. Root colonization study confirmed that the introduced <span style="font-size:15.0pt;mso-bidi-font-size:8.0pt;line-height:115%; font-family:" times="" new="" roman","serif";mso-fareast-font-family:"times="" roman";="" mso-ansi-language:en-us;mso-fareast-language:en-us;mso-bidi-language:ar-sa"="">bacteria colonized the roots and occupied 23-25% of total aerobic bacteria, which was confirmed using dual antibiotic (nalidixic acid and streptomycin sulphate) resistant mutant strain . T he results obtained through this investigation suggested the potentiality of the strain BS2 to be used as a plant growth promoter and suppressor of wilt pathogen. </span

Influence of charge traps in carbon nanodots on gas interaction

The nonlinear electrical characteristic of carbon nanodots (CNDs) has revealed important physical phenomena of charge trapping playing a dominant role in surface interactions. Functional groups on the surface of CNDs attract ambient water molecules which in turn act as charge traps and give rise to electrical hysteresis that plays a dominant role in understanding charge transport in CNDs on surface interactions. Hysteresis in the current-voltage response is further utilized to study the interaction of the CNDs with nitrogen dioxide gas as an external stimuli. The hysteresis area is observed to be dependent on the time of gas interaction with the CNDs, therefore revealing the interaction mechanism of the CNDs with the gas