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When a magnetic moment is embedded in a metal, it captures itinerant electrons to form the Kondo cloud1,2, which can spread out over a few micrometres3,4. For a metal with dense magnetic impurities such that Kondo clouds overlap with each other, correlated ground states are formed. When the impurities form a regular lattice, the result is a heavy fermion or anti-ferromagnetic order depending on the dominant interaction5,6. Even in the case of random impurities, overlapping Kondo clouds are expected to form a coherent ground state. Here, we examine this issue by performing electrical transport and high-precision tunnelling density-of-states (DOS) spectroscopy measurements in a highly P-doped crystalline silicon metal where disorder-induced localized magnetic moments exist7. We detect the Kondo effect in the resistivity of the Si metal below 2 K and an exotic pseudogap in the DOS with gap edge peaks at a Fermi energy below 100 mK. The DOS gap and peaks are tuned by applying an external magnetic field and transformed into a metallic Altshuler-Aronov gap8 in the paramagnetic disordered Fermi liquid (DFL) phase. We interpret this phenomenon as the Kondo condensation, the formation of a correlated ground state of overlapping Kondo clouds, and its transition to a DFL. The boundary between the Kondo condensation and DFL phases is identified by analysing distinct DOS spectra in the magnetic field-temperature plane. A detailed theoretical analysis using a holographic method 9 , 10 , 11 reproduces the unusual DOS spectra, 1, supporting our scenario. Our work demonstrates the observation of the magnetic version of Bardeen-Cooper-Shrieffer (BCS) pair condensation and will be useful for understanding complex Kondo systems., Comment: 34 pages,5+6 figures, accepted in nature physics

The layer-by-layer mesoporous nanohybrids of Ni-Cr-layered double hydroxide (Ni-Cr-LDH) and polyoxotungstate nanoclusters (Ni-Cr-LDH-POW) are prepared via exfoliation reassembling strategy. The intercalative hybridization of Ni-Cr-LDH with POW nanoclusters leads to forming a layer-by-layer stacking framework with significant expansion of the interplanar spacing and surface area. The aqueous hybrid supercapacitor (AHSC) and all-solid-state hybrid supercapacitor (SSHSC) devices are fabricated using Ni-Cr-LDH-POW nanohybrid as a cathode and reduced graphene oxide (rGO) as an anode material. Notably, the NCW-2//rGO AHSC device delivers an ED of 43 Wh kg

In everyday life superior lithium-ion batteries (LIB) with fast charging ability have become a valuable asset. The LIB performance of anode composite copper cobalt tin sulphide (Cu2CoSnS4; CCTS) electrodes, which were fabricated using a simple and easy hydrothermal method, was investigated. The electrochemical charge storage performance of the CCTS anode demonstrated sustainability, high-rate capability and efficiency. The CCTS anode exhibited a first discharge capacity of 914.5 mAhg−1 and an average specific capacity of 198.7 mAhg−1 in consecutive cycles at a current density of 0.1 Ag−1. It had a capacity retention of ~62.0% and a coulombic efficiency of more than 83% after over 100 cycles, demonstrating its excellent cycling performance and reversibility. It can be an alternative anode to other established electrode materials for real battery applications.

Kesterite Cu2ZnSnS4 (CZTS)-based solar devices have become a popular alternative to copper indium gallium selenide (CIGS) due to its outstanding properties such as high efficiency, non-toxicity, cost-effectiveness, suitable optoelectrical properties, and earth-abundancy. In this study, we directly fabricated CZTS films via a single-step spray pyrolysis technique, in contrast to conventional techniques where post sulfurization is required. The spray deposited CZTS films are investigated for their optical, structural, and electrical properties. The X-ray diffraction (XRD) and Raman analysis study revealed the synthesis of the phase-pure kesterite CZTS films without impurity phases. Large crystallites of CZTS are obtained at a deposition temperature of 400 °C, exhibiting a porous granular morphology with different grain sizes upon temperature variation. The size-dependent optical properties revealed that the CZTS films exhibited admirable visible light absorption of 105 cm−1 and an electronic bandgap ranging between 1.42 and 1.58 eV. The minimum dielectric loss obtained for optimized CZTS due to fewer intrinsic defects confirmed the materials’ applicability. Thus, the study provides a simple, viable route to fabricate CZTS without post-treatment to build affordable solar cells.

Water-stable, lead-free zero-dimensional (0D) organic–inorganic hybrid colloidal tin(IV) perovskite, A2SnX6 (A is a monocationic organic ion and X is a halide) nanocrystals (NCs) with high photoluminescence (PL) quantum yield (QY) have rarely been explored. Herein, we report solution-processed colloidal NCs of blue light-emitting T2SnCl6 and orange light-emitting T2Sn1-xSbxCl6 [T+ = tetramethylammonium cation] from their corresponding single crystals (SCs). These colloidal NCs are well-dispersible in non-polar solvents, thereby maintaining their bright emission. This paves the way for fabricating homogeneous thin films of these NCs. Due to organic cation (T+)-controlled large spin–orbit coupling (SOC), the T2Sn1-xSbxCl6 NCs exhibit bright orange emission with an enhancement in PL QY of 41% compared to their bulk counterpart. Furthermore, we explore T2Sn1-xBixCl6 and T2Sn1-x-yBixSbyCl6 SCs, which show blue and green emission, respectively; the latter is attributed to the newly formed Sb 5p and Sb 5 s orbital-driven band structures confirmed by applying density functional theory (DFT) calculations. The SCs and NCs exhibit excellent stability in water under ambient conditions because of the in-situ generation of a hydrophobic and oxygen-resistant passivating layer of oxychloride in the presence of water. Our findings open a pathway for designing lead-free perovskites materials for thin-film-based optoelectronic devices.

Facile template–free controllable growth of freestanding polyhedron–like CoS onto microporous Ni foam with three-dimensional architecture via a mild hydrothermal technique is reported. The as-obtained CoS catalyst phase was first tailored to N-Co9S8 (nitrogen doped Co9S8), and its inherent reaction kinetics and conductivity were then enhanced through sulfur incorporation via a hydrothermal process. The electrochemical performance of the pristine CoS and a sulfur-enriched N-Co9S8 (S, N-Co9S8) electrode in alkaline 1.0 M KOH was examined. The optimized polyhedral S, N-Co9S8 structured catalyst exhibits significantly enhanced electrocatalytic activity for both oxygen evolution reaction (OER) and hydrogen evolution reaction (HER). As a result, low overpotentials of 244 and −92 mV is required to achieve the current density of 10 mA cm−2 for the OER and HER, respectively. Furthermore, when the polyhedral S, N-Co9S8 catalyst was employed as a bifunctional catalyst in a two-electrode electrolyzer cell exhibiting a cell voltage of 1.549 V at 10 mA cm−2 and demonstrates excellent long-term (50 hrs.) chronopotentiometric electrolysis at various current rate, reveals excellent bifunctional OER and HER activities at different applied current densities. The superior OER and HER activities of the S, N-Co9S8 catalyst is result of the improved electronic conductivity and enhanced intrinsic reaction kinetics, which led to the enhanced electrocatalytically active sites after the incorporation of heteroatoms in the catalyst structure.

The oxygen evolution reaction (OER) plays a key role in determining the performance of overall water splitting, while a core technological consideration is the development of cost-effective, efficient, and durable catalysts. Here, we demonstrate a robust reduced Fe-oxide@NiCo2O4 bilayered non-precious-metal oxide composite as a highly efficient OER catalyst in an alkaline medium. A bilayered oxide composite film with an interconnected nanoflake morphology (Fe2O3@NiCo2O4) is reduced in an aqueous NaBH4 solution, which results in a mosslike Fe3O4@NiCo2O4 (reduced Fe-oxide@NiCo2O4; rFNCO) nanostructured film with an enhanced electrochemical surface area. The rFNCO film demonstrates an outstanding OER activity with an extraordinary low overpotential of 189 mV at 10 mA cm–2 (246 mV at 100 mA cm–2) and a remarkably small Tafel slope of 32 mV dec–1. The film also shows excellent durability for more than 50 h of continuous operation, even at 100 mA cm–2. Furthermore, density functional theory calculations suggest that the unintentionally in situ doped Ni during the reduction reaction possibly improves the OER performance of the rFNCO catalyst shifting d-band centers of both Fe and Ni active sites.

Halide perovskites (HPs) are used in various applications, including solar cells, light-emitting diodes, lasers, and photodetectors. These materials have recently received a great deal of attention as high-energy radiation detectors and scintillators due to their excellent light yield, mobility-lifetime product (µτ), and X-ray sensitivity. In addition, due to their solution-processability and low cost, perovskite materials could be used to produce thick perovskite films across wide areas, allowing for low-dose X-ray imaging. Perovskite-based scintillators and detectors could eventually replace commercialized products like thallium‐doped cesium iodide (CsI:Tl) and amorphous silicon (Si). Here, we review all of the key properties of HPs, the relevant terminology necessary for radiation detection and scintillation, the physical mechanisms underlying their operation, the fabrication process, and perovskite crystals and thin-films of varying dimensionality used for high-energy radiation detection. We also cover the critical issues and solutions that HPs as detectors, scintillators, and imagers face.

In the rapid development of organic light-emitting diodes (OLEDs), phosphorescent transition metal complexes have played a crucial role as the most promising candidates for next generation display and lighting applications. However, most devices are fabricated using iridium and platinum-based complexes which are expensive and available in very limited quantities, whereas using relatively abundant organometallic complexes for fabrication results mostly in inefficient performance results. To overcome these issues, we have synthesized tetra copper iodide with tetra triphenyl cage like structure (denoted as CIPh) as an emerging class of luminescent material by mechanochemical grinding followed by thermal treatment for application in white OLED. The CIPh complex exhibits considerable quantum yield and a millisecond decay lifetime. Phosphorescent OLEDs were fabricated using CIPh complex as emitter shows a remarkable performance with external quantum efficiency and current efficiency of 5.28 % and 22.76 cd/A, with a high brightness of 4200 cd m

Ruddlesden-Popper (RP) phases (An+1BnO3n+1, n = 1, 2,···) have attracted intensive research with diverse functionalities for device applications. However, the realization of a high-quality RP-phase film is hindered by the formation of out-of-phase boundaries (OPBs) that occur at terrace edges, originating from lattice mismatch in the c-axis direction with the A'B'O3 (n = ∞) substrate. Here, using strontium ruthenate RP-phase Sr2RuO4 (n = 1) as a model system, an experimental approach for suppressing OPBs was developed. By tuning the growth parameters, the Sr3Ru2O7 (n = 2) phase was formed in a controlled manner near the film-substrate interface. This higher-order RP-phase then blocked the subsequent formation of OPBs, resulting in nearly defect-free Sr2RuO4 layer at the upper region of the film. Consequently, the Sr2RuO4 thin films exhibited superconductivity up to 1.15 K, which is the highest among Sr2RuO4 films grown by pulsed laser deposition. This work paves the way for synthesizing pristine RP-phase heterostructures and exploring their unique physical properties.

Despite the considerable efforts in advancing nonprecious-metal candidates as oxygen evolution reaction (OER) electrocatalysts, cost-effective production of efficient and stable catalysts via simple synthesis routes remains to be realized. We report on the experimental and density functional theory (DFT) guidelines of nickel (Ni)–vanadium (V) layered double hydroxides (LDHs) to prepare an optimal electrocatalyst by changing its composition ratio. The optimized Ni0.75V0.25 LDH exhibits the ultralow overpotentials of 200 and 292 mV at the current densities of 10 and 400 mA cm–2, respectively, a long-term durability of more than 100 h at 10 mA cm–2, and an extremely low Tafel slope of 48.3 mV dec–1. These findings can provide guidance for the facile optimal design of state-of-the-art water oxidation catalysts by using LDHs for large-scale practical applications. The enhanced catalytic performance can be attributed to a lower hydrogen desorption energy and the presence of many open O sites, which can promote the initiation of the OER reaction.

Developing multicomponent superlattices (SLs) using lead halide perovskite nanocrystals (NCs) is challenging due to weak ionic bonding and the high ionic mobility of halide ions. Recently, Kovalenko et al. developed multicomponent SLs, including binary cubic SLs, binary perovskite-like SLs, ternary perovskite-like SLs, and columnar binary SLs.

Commercial lithium–ion batteries (LIBs) are insufficient to bridge the energy density gap between demand and supply in advanced heavy and portable electronic devices because of graphite anodes (poor theoretical capacity: 372 mAh g−1). Ternary chalcogenide metal‐sulfides are promising as alternative anode materials in high power and energy densities but suffer from capacity fading with poor long‐term cycling stability due to the dissolution of polysulfide species created during the lithium‐ion insertion/de‐insertion process. Here, we report the hydrothermal synthesis of graphene integrated CuCo2S4 microparticles as a high‐capacity and sustainable anode material for LIBs. We solve the concentration gradient of lithium polysulfide at the interface of electrode/electrolyte via integrating graphene into the active metal sulfide anode material. The mechanically flexible and highly conductive nature of graphene helps relieve undesirable elongation and shrinkage during battery cycling, suppressing active material dissolution and enhancing electron/ion transport through the electrochemical double‐layer (EDL). Our one step approach demonstrates towards the practical application of advanced metal sulfide anodes for LIBs.

Herein a method is proposed for engineering the electronic properties (including the band structure) of diamond via surface hybridization with graphene. Graphene layers (5–50 nm in thickness) were grown vertically onto a polished 〈110〉 textured polycrystalline diamond plate (1 × 1 cm2) (vGr-diamond) at ∼1300 °C via hydrogen plasma etching in a chemical vapor deposition (CVD) chamber. Due to the crystallographic relationship, the graphene layers embed at an angle of 30° to the diamond surface comprising the (110) planes. The epitaxial relationship is demonstrated via low angle X-ray diffraction (XRD), the XRD rocking curve, Raman and scanning electron microscopy. With hybridization, the diamond sample reveals a strong photoluminescent (PL) signal at ∼2.78 eV (∼450 nm). The peak was assigned to the ‘interface defects’ of the vGr-diamond hybrid structure, which are a type of ‘surface defect’ of the CVD diamond that generates a peak at ∼2.69 eV. The blue shift (∼90 meV) of the interface defects is due to the compressive strain of ∼3% applied to the interface atoms. Simulations indicate that the hybrid structures possess a finite band gap of 1.85–0.25 eV, which decreases upon increasing the thickness of the graphene layers to ∼1.4 nm. The appearance of a small band gap was attributed to the compressive strain. These findings may provide a route for diamond to become a platform for next generation and extreme electronic devices.

The use of electrodes capable of functioning as both electrochromic windows and energy storage devices has been extended from green building development to various electronics and displays to promote more efficient energy consumption. Herein, we report the electrochromic energy storage of bimetallic NiV oxide (NiVO) thin films fabricated using chemical bath deposition. The best optimized NiVO electrode with a Ni/V ratio of 3 exhibits superior electronic conductivity and a large electrochemical surface area, which are beneficial for enhancing electrochemical performance. The color switches between semitransparent (a discharged state) and dark brown (a charged state) with excellent reproducibility because of the intercalation and deintercalation of OH- ions in an alkaline KOH electrolyte. A specific capacity of 2403 F g-1, a coloration efficiency of 63.18 cm2 C-1, and an outstanding optical modulation of 68% are achieved. The NiVO electrode also demonstrates ultrafast coloration and bleaching behavior (1.52 and 4.79 s, respectively), which are considerably faster than those demonstrated by the NiO electrode (9.03 and 38.87 s). It retains 91.95% capacity after 2000 charge-discharge cycles, much higher than that of the NiO electrode (83.47%), indicating that it has significant potential for use in smart energy storage applications. The superior electrochemical performance of the best NiVO compound electrode with an optimum Ni/V compositional ratio is due to the synergetic effect between the high electrochemically active surface area induced by V-doping-improved redox kinetics (low charge-transfer resistance) and fast ion diffusion, which provides a facile charge transport pathway at the electrolyte/electrode interface.

The invention of cost-effective, clean, and eco-friendly energy storage technology has been capturing a lot of worldwide interest. Herein, biogenically synthesized TiO

High-density CuCo2O4 nanosheets are grown on Ni foam using electrodeposition followed by air annealing for a Li-ion battery anode. The anode exhibits a high discharge capacity of 1244 mAh/g at 0.1 A/g (82% coulombic efficiency) and excellent high-rate performance with 95% capacity retention (1100 mAh/g after 200 cycles at 1 A/g). The outstanding battery performance of the CuCo2O4 anode is attributed to its binder-free direct contact to the current collector and high-density nanosheet morphology. The present experimental findings demonstrate that the electrodeposited binder-free CuCo2O4 material may serve as a safe, low-cost, long-cycle life anode for Li-ion batteries.

Water-stable, lead-free zero-dimensional (0D) organic-inorganic hybrid colloidal tin(IV) perovskite, A

The surprising recent observation of highly emissive triplet-states in lead halide perovskites accounts for their orders-of-magnitude brighter optical signals and high quantum efficiencies compared to other semiconductors. This makes them attractive for future optoelectronic applications, especially in bright low-threshold nanolasers. While nonresonantly pumped lasing from all-inorganic lead-halide perovskites is now well-established as an attractive pathway to scalable low-power laser sources for nano-optoelectronics, here we showcase a resonant optical pumping scheme on a fast triplet-state in CsPbBr3 nanocrystals. The scheme allows us to realize a polarized triplet-laser source that dramatically enhances the coherent signal by 1 order of magnitude while suppressing noncoherent contributions. The result is a source with highly attractive technological characteristics, including a bright and polarized signal and a high stimulated-to-spontaneous emission signal contrast that can be filtered to enhance spectral purity. The emission is generated by pumping selectively on a weakly confined excitonic state with a Bohr radius ∼10 nm in the nanocrystals. The exciton fine-structure is revealed by the energy-splitting resulting from confinement in nanocrystals with tetragonal symmetry. We use a linear polarizer to resolve 2-fold nondegenerate sublevels in the triplet exciton and use photoluminescence excitation spectroscopy to determine the energy of the state before pumping it resonantly.

Synthesizing colloidal nanocrystals (NCs) with long-term stable under ambient conditions via appropriate ligands capping is highly challenging. Herein, the rapid synthesis of CsPbBr3 colloidal NCs at room temperature using polyvinylpyrrolidone as the primary ligand is demonstrated. The addition of ethylene glycol stabilizes the colloidal NCs and enhance their photoluminescence by ∼ 5-fold. Colloidal NCs have a net negative surface charge, which enables the direct electrophoretic deposition of a polymer-induced all-inorganic CsPbBr3 NC film with ultra-high stability under ambient conditions at relative humidity of 55% for 240 days. As an example of the application of the CsPbBr3 NC film in an optoelectronic device, a hybrid MoS2/CsPbBr3 field-effect phototransistor is fabricated, which exhibits a detectivity of 9×1012 Jones and an ultra-high responsivity of 1.2×107 A W−1 under the illumination of 450-nm laser at 4.4 pW. The noble and practical methods applied in our CsPbBr3 NC films could be extended to produce various types of uniform NC films over a large geometrical area with outstanding long-term environmental stability, holding significant promise for use in a broad range of advanced optoelectronic devices.

Compared with solid scintillators, liquid scintillators have limited capability in dosimetry and radiography due to their relatively low light yields. Here, we report a new generation of highly efficient and low-cost liquid scintillators constructed by surface hybridisation of colloidal metal halide perovskite CsPbA3 (A: Cl, Br, I) nanocrystals (NCs) with organic molecules (2,5-diphenyloxazole). The hybrid liquid scintillators, compared to state-of-the-art CsI and Gd2O2S, demonstrate markedly highly competitive radioluminescence quantum yields under X-ray irradiation typically employed in diagnosis and treatment. Experimental and theoretical analyses suggest that the enhanced quantum yield is associated with X-ray photon-induced charge transfer from the organic molecules to the NCs. High-resolution X-ray imaging is demonstrated using a hybrid CsPbBr3 NC-based liquid scintillator. The novel X-ray scintillation mechanism in our hybrid scintillators could be extended to enhance the quantum yield of various types of scintillators, enabling low-dose radiation detection in various fields, including fundamental science and imaging., Optics: Hybrid liquid scintillator with enhanced light output A hybrid liquid scintillator could be used in low-dose radiation detectors for use in imaging applications and scientific research. Highly sensitive X-ray detection is increasingly being used in industrial and military applications and for fundamental scientific research. Although liquid scintillators are more resilient to damage from exposure to intense radiation than crystalline or plastic scintillators, they have relatively low density and low radioluminescence quantum yields, both of which are critical for achieving high resolution and contrast in X-ray imaging. Now, a team of Korean researchers led by Hyunsik Im from Dongguk University has created a liquid scintillator detector made from colloidal perovskite metal halide nanocrystals and organic molecules with a significantly enhanced quantum yield. The novel device could see use in a wide range of X-ray technologies that require high-performance detectors and imagers.

The high-activity of metallic nanofilament array (NFA) embedded tungsten oxide (WO3) bifunctional electrodes for electrochromism and electrochemical energy storage is presented. The NFA reduces charge transfer resistance and increases the electrochemically active surface area at the electrode–electrolyte interface. The NFA-embedded WO3 electrode exhibits a specific capacity of 214 F g−1 (pristine WO3: 133 F g−1) at 0.25 mA cm−2, excellent cycling stability with ∼92% capacitance retention after 2000 cycles (pristine WO3: ∼75% capacitance retention) and a coloration efficiency of 128 cm2 C−1 (pristine WO3: 91 cm2 C−1) with superb optical modulation. These properties are significantly more advanced compared to the pristine WO3 electrode and superior to previously reported WO3-based composites and nanostructured materials.

Large scale, cost-efficient, durable, and non-noble metal catalysts for overall water splitting in alkaline-anion-exchange-membrane-water-electrolyzer (AAEMWE) are highly demanded for the clean hydrogen economy. Meanwhile, V- and Co-based bimetallic oxide materials were rarely reported for overall water splitting in AAEMWE. Herein, we demonstrate that the self-supported oxovanadate-doped cobalt carbonate (VCoCOx@NF) on nickel foam (NF) is a high-performance overall water-splitting catalyst in AAEMWE. The as-prepared VCoCOx@NF catalyst demonstrates high activity for both hydrogen and oxygen evolution reactions (HER and OER) in alkaline media, with a current density (j) of 10 mA cm−2 at overpotentials of 63 mV and 240 mV, respectively. Assembled as a conventional electrolyzer for overall water splitting, VCoCOx@NF as both anode and cathode in 1 M KOH operates at low cell voltages of 1.54 and 1.74 V at 10 and 100 mA cm−2, respectively, superior to the Ir/C−Pt/C@NF electrolyzer (1.59 and 1.86 V, respectively). First principle calculations show that the remarkable HER and OER at the Co site are due to the doping of V species, which reduces the overpotential by shifting the d-electron states of Co towards the Fermi-level. Besides, an AAEMWE cell fabricated with the VCoCOx@NF catalyst delivers j = 200 mA cm−2 at 2.01 V in deionized water, lower than the expensive commercial IrOx-Pt/C@Au/Ti electrolyzer (2.06 V). This finding provides the stage for large-scale hydrogen production by utilizing the V- and Co-based bimetallic oxide materials.

A supercapacitor is well recognized as one of emerging energy sources for powering electronic devices in our daily life. Although various kind of supercapacitors have been designed and demonstrated, their market aspect could become advanced if the utilisation of other physicochemical properties (e.g. optical) is incorporated in the electrode. Herein, we present an electrochromic supercapacitor (smart supercapacitor) based on a nanoflake NiMoO4 thin film which is fabricated using a facile and well-controlled successive ionic layer adsorption and reaction (SILAR) technique. The polycrystalline nanoflake NiMoO4 electrode exhibits a large electrochemically active surface area of ~ 96.3 cm2. Its nanoporous architecture provides an easy pathway for the intercalation and de-intercalation of ions. The nanoflake NiMoO4 electrode is dark-brown in the charged state and becomes transparent in the discharged state with a high optical modulation of 57%. The electrode shows a high specific capacity of 1853 Fg–1 at a current rate of 1 Ag–1 with a good coloration efficiency of 31.44 cm2/C. Dynamic visual information is obtained when the electrode is charged at different potentials, reflecting the level of energy storage in the device. The device retains 65% capacity after 2500 charge-discharge cycles compared with its initial capacity. The excellent performance of the nanoflake NiMoO4 based smart supercapacitor is associated with the synergetic effect of nanoporous morphology with a large electrochemically active surface area and desired chemical composition for redox reaction.

Due to acute ammonium toxicity, it is always desirable to find a cheaper and abundant electro-catalyst other than platinum, iridium oxide, boron diamond etc with a high selectivity and negligible de-activation for its oxidation. Also ammonium is not known for electricity generation except biological nitrification process. So this paper elucidates the studies of compost as a novel electro-catalyst in a ammonium fuel cell configuration. These studies are done by varying type of electrodes & compost as well as ammonium concentration. Bi-polar cyclic voltammetry, electrochemical impedance spectroscopy, temperature dependence, cyclic stability and chrono-amperometry techniques are used to study compost. Cow dung based compost is found to show the best electro-catalytic activity. IV measurements are conducted to study power generation in tune with the electro-catalytic activity. Finally, polarization and sustainability measurements are done on a comparatively larger fuel cell to check the size scalability. The results shows that the maximum power density is 108 mW/m2 and this multifunctional device can be fueled after every 12 h for continuous operation and with negligible de-activation of electro-catalyst. These studies opens a window for doing further advanced research in compost triggered electro-catalysis to make multifunctional fuel cell devices for solving environmental and energy issues together.

The temperature-dependent performance of a Li 2 ZnTi 3 O 8 (LZTO) anode and the ultrafast-charging activity of a Li-ion battery were investigated. The LZTO anode operates at different temperatures between − 5 and 55 °C and in this work its sustainability is discussed in terms of storage performance. It delivered a discharge capacity of 181.3 mA h g −1 at 25 °C, which increased to 227.3 mA h g −1 at 40 °C and 131.2 mA h g −1 at − 5 °C. The variation in the discharge capacity with temperature is associated with the reaction kinetics and the change in internal resistance. It showed a capacity retention of 64% and a coulombic efficiency of 98% over 500 cycles. Exhibiting a discharge capacity of 107 mA h g −1 , the LZTO anode was sustainable over 100 charge-discharge cycles at an ultra-high charging rate of 10 Ag −1 . The reaction kinetics estimated from a cyclic voltammetry analysis at high scan rates revealed a capacitive-type storage mechanism.