Organic template-assisted green synthesis of CoMoO4 nanomaterials for the investigation of energy storage properties

Cobalt molybdate nanoflowers decorated bio-waste derived porous activated carbon nanocomposite: A high performance electrode material for supercapacitors

In this work, we report a supercapacitor electrode material based on nano-flower like cobalt molybdate decorated on porous activated carbon derived from waste onion peels (β-CoMoO4-POAC). The obtained POAC exhibits highly porous structure and after the hydrothermal treatment with salts of cobalt and molybdenum, we observed a uniform distribution of β-cobalt molybdate (β-CoMoO4) as nano-flowers on the surface of POAC. The chemical composition, morphology and porosity of the materials were thoroughly analyzed using field emission scanning electron microscopy, X-ray photoelectron spectroscopy, X-ray diffraction, infrared spectroscopy and Brunauer-Emmet-Teller surface area measurement. Due to its flower like and highly porous morphology, β-CoMoO4@POAC exhibits a high specific capacitance of 1110.72 F/g at a current density of 1 mA/cm2 with superior cyclic retention of 96.03% after 2000 cycles. The best electrochemical performance exhibited by β-CoMoO4@POAC is mainly due to its high surface area and porous nature of the material which assists in active transport of ions. This study reveals the exceptional electrochemical properties of β-CoMoO4@POAC which could be considered as a potential material for advanced energy storage devices.

Waste Citrus reticulata Assisted Preparation of Cobalt Oxide Nanoparticles for Supercapacitors

The green, sustainable, and inexpensive creation of novel materials, primarily nanoparticles, with effective energy-storing properties, is key to addressing both the rising demand for energy storage and the mounting environmental concerns throughout the world. Here, an orange peel extract is used to make cobalt oxide nanoparticles from cobalt nitrate hexahydrate. The orange peel extract has Citrus reticulata, which is a key biological component that acts as a ligand and a reducing agent during the formation of nanoparticles. Additionally, the same nanoparticles were also obtained from various precursors for phase and electrochemical behavior comparisons. The prepared Co-nanoparticles were also sulfurized and phosphorized to enhance the electrochemical properties. The synthesized samples were characterized using scanning electron microscopic and X-ray diffraction techniques. The cobalt oxide nanoparticle showed a specific capacitance of 90 F/g at 1 A/g, whereas the cobalt sulfide and phosphide samples delivered an improved specific capacitance of 98 F/g and 185 F/g at 1 A/g. The phosphide-based nanoparticles offer more than 85% capacitance retention after 5000 cycles. This study offers a green strategy to prepare nanostructured materials for energy applications.

Phyto-synthesized facile Pd/NiOPdO ternary nanocomposite for electrochemical supercapacitor applications

The natural phyto bio-factories were successfully utilized for the cost-effective synthesis of facile Pd/NiOPdO ternary nanocomposite for energy storage application with enhanced electro-active site.

Phyto-inspired Cu/Bi oxide-based nanocomposites: synthesis, characterization, and energy relevant investigation

A modified and sustainable approach is reported in this research for the synthesis of a spherical-shaped CuO–Bi₂O₃ electrode material for electrochemical studies. Aqueous extract derived from the plant Amaranthus viridis L. (Amaranthaceae) (AVL) was used as a reducing agent for morphological control of the synthesis of CuO–Bi₂O₃ nanocomposites. The modified nanomaterial revealed an average crystal size of 49 ± 2 nm, which matches very well with scanning electron microscopy (SEM) findings. Furthermore, the synthesized material was characterized using Fourier-transform infrared spectroscopy, field emission SEM and energy-dispersive spectroscopy. The optical band gap energy of 3.45 eV was calculated using a Tauc plot. Finally, the bioorganic framework-derived CuO–Bi₂O₃ electrode was tested for energy generating and storage applications and the results revealed a capacitance of 389 F g⁻¹ by cyclic voltammetry, with a maximum energy density of 12 W h kg⁻¹ and power density of 5 kW kg⁻¹. Hydrogen evolution reaction and oxygen evolution reaction studies showed good potential of CuO–Bi₂O₃ as an electrocatalyst for water splitting, with maximum efficiency of the electrode up to 16.5 hours.

Spherical-shaped CuO–Bi₂O₃ electrode material and its electrochemical studies.

A Survey on Analytical Methods for the Characterization of Green Synthesized Nanomaterials

Nowadays, nanotechnologies are well established and the uses of a great variety of nanomaterials show exponential growth. The development of green synthesis procedures experienced a great development thanks to the contribution of researchers of diverse origins. The versatility of green chemistry allows producing a wide range of organic and inorganic nanomaterials with numerous promising applications. In all cases, it is of paramount importance to carefully characterize the resulting nanomaterials because their properties will determine their correct performance to accomplish the function to which they were synthesized or even their detrimental effects like nanotoxicological behavior. This review provides an overview of frequently employed characterization methods and their applications for green synthesized nanomaterials. However, while several different nanoscale materials and their associated green construction methodology are being developed, other important techniques would be extensively incorporated into this field soon. The aim is to encourage researchers in the field to employ a variety of these techniques for achieving an exhaustive characterization of new nanomaterials and for contributing to the development of validated green synthesis procedures.

Adsorption and sugarcane-bagasse-derived activated carbon-based mitigation of 1-[2-(2-chloroethoxy)phenyl]sulfonyl-3-(4-methoxy-6-methyl-1,3,5-triazin-2-yl) urea-contaminated soils

Burgeoning pesticide usage in agriculture sector required to be evaluated by assessing the adsorption rate in soils. The herbicide triasulfuron was used in this research to analyze its sorption behavior in seven distinct soils using batch equilibrium methodology. The adsorption coefficient (Kd) values ranged from the 3.32 to 29.7 µg/mL. Peshawar soil displayed the highest Kd value because of the distinct physiochemical properties when compared with the other six samples. Gibbs free energy exhibited negative values displaying less contact between soil particles and pesticides, showing the exothermic nature of the phenomena. A negative association was observed between the pH of the soil samples and Kd (R2 = −0.71) but a direct relation with the organic content (R2 = 0.74). Triasulfuron mitigation was performed by the economical remediation of soils using acid-activated charcoal prepped from Saccharum officinarum husk. Activated carbon derived from biomass displayed the great potential for triasulfuron removal from soils.

Ecospheric Decontamination Attained via Green Nanobiotechnological NiO-Based Nanocatalyst Derived from Nature's Biofactories

INTRODUCTION

Water contamination from dye effluents from various industrial sources has become a major challenge of the scientific community that is difficult to remediate using orthodox chemical and biological procedures. As such, there is a need for more suitable and cost-effective ways to treat such effluents. The present work describes a green-synthesis approach for preparation of three types of Ni-based oxides as effective catalytic materials to remove environmental pollutants. Metal oxide nanomaterials are cheap, abundant, and ecofriendly earth metals, and thus are promising materials for catalytic applications for environmental detoxification.

METHODS

An aqueous leaf extract of Prunus persica was used as a reducing agent for the synthesis of NiO, NiO-PdO, and NiO-ZnO nanoparticles (NPs). The leaf extract was treated with each metal-salt precursor based on sol-gel synthesis, and then the final procured NPs were analyzed by spectroscopic techniques for structural and morphological makeup. The pure NPs were further explored for catalytic degradation of hazardous aqueous dye at ambient conditions, instead of following any sophisticated experimental conditions.

RESULTS AND DISCUSSION

Morphological features revealed the pure formation of NiO, NiO-ZnO, and NiO-PdO NPs of size <100nm, characterized by X-ray diffraction spectroscopy and scanning electron microscopy. Catalytic tests with methyl orange revealed the remediation potential of synthesized material, showing the pseudo-first order kinetics (R 2<1) for NiO, NiO-PdO, and NiO-ZnO. NiO-ZnO gave outstanding results both in dark (R 2=0.88) and light (R 2=0.82) with degradation percentage of 99% (dark) in comparison with the other two catalysts. Moreover, excellent catalyst stability for NiO-ZnO) was observed, even after the fourth cycle, under both light and dark conditions and was separated easily during centrifugation.

CONCLUSION

Although all three materials depicted the degradation potential with good stability, but the NiO-ZnO catalyst was the best catalytic material in the present investigation, with prominent degradation percentage, and can be considered as an efficient catalytic material. Thus, we conclude that P. persica-inspired catalytic material could pave the path toward environmental remediation, alternative clean energy, and other biological applications.

Bio Framework-Derived Facile MoO3-NiO-PdO-Pd Nanomaterial for Detoxification of Organic Pollutants

INTRODUCTION

The catalytic behavior of metal oxide nanomaterials for removal of organic pollutants under dark ambient conditions, without any additional stimulant, is of great interest among the scientific community.

METHODS

In this account, a nanomaterial of ternary metal oxides (MoO3-NiO-PdO-Pd) was synthesized via greener approach and was explored for degradation of methyl orange in water environment in dark ambient conditions in comparison with light conditions. The biochemical species of Abies pindrow were treated with aqueous solution of precursor's salt following sol gel synthesis strategy. We further attuned morphology and chemistry of MoO3-NiO-PdO-Pd by incorporating bioactive compounds of A. pindrow.

RESULT AND DISCUSSION

The bio-fabricated MoO3-NiO-PdO-Pd revealed outstanding catalytic behavior with 92% degradation of methyl orange within 15 min in the dark at ambient temperature and pressure. Whereas, in the presence of visible light irritation, the catalyst degraded 97% of methyl orange in 15 min. According to the reaction kinetics of degradation, the catalysts illustrated good stability in light (R2=0.93) as well as in dark conditions (R2=0.98). Furthermore, the outstanding reusability and recyclability of the synthesized nanomaterial was observed for four runs of the experiment under dark and light conditions.

CONCLUSION

Therefore, A. pindrow-synthesized MoO3-NiO-PdO-Pd nanocatalyst demonstrated significant potential for detoxification of organic pollutants for water remediation.

Green synthesis of ZnO–Co3O4 nanocomposite using facile foliar fuel and investigation of its electrochemical behaviour for supercapacitors

Currently, the sustainable fabrication of supercapacitors with enhanced properties is one of the significant research hotspots.