Electrochemical Performance of Delafossite, AgFeO2: A Pseudo-Capacitive Electrode in Neutral Aqueous Na2SO4 Electrolyte

Layered delafossite AgFeO2 with open channel structure is envisaged as a pseudo capacitor electrode using Fe2+/ Fe3+ redox couple. A simple co-precipitation method was employed for the phase formation of delafossite AgFeO2 resulting in a mixture of 2H and 3R-phase. Phase tuning of 2H phase was done by controlling the calcination conditions and characterizing by powder XRD, FT-IR, and Raman methods. 2H AgFeO2 was used to synthesize as a majority phase because it have the larger inter layer spacing than 3R phase shown. HRTEM study confirms the formation 2H phase in majority. All of the synthesized samples exhibit predominantly faradic battery-type redox behavior along with surface charge storage. Flower like microarchitectures of AgFeO2 show outstanding electrochemical performance with high specific capacity of 110.4 F/g at 1 A/g current density, that retained up to 89% after 2000th times charge/discharge in 1M Na2SO4 electrolyte. In an asymmetric device mode, AFO-400//AC full cell exhibits superior electrochemical performance by delivering high energy density (33.5 Wh/kg) and high power density (454.3 W/kg) with excellent cycling stability (86% retention after 2000th cycles). The results clearly demonstrate that the synthesized delafossite AgFeO2 containing mixture of 2H and 3R-phases have remarkable potential to be used as a negative electrode material for supercapacitor and other energy storage technologies

Synthesis, Characterizaiton of CuO nano-rod for Supercapacitor Applications

A novel approach solvothermal synthesis method has been utilized to prepare CuO nanorods for electrochemical capacitors. A new method of synthesis has been adopted for the synthesis of CuO nanostructures. Structural, morphological features of the prepared material were studied by XRD and SEM respectively. Electrochemical supercapacitive performances of the modified electrode material were also analyzed by electrochemical workstation in three-electrode system. This material found to exhibit pesudocapacitive behavior with high capacitance of 135.23 F/g at the prevalent density of 1 A/g in 1M Na2SO4 electrolyte solution, proving a suitable candidate electrode material for supercapacitor applications.

Synthesis, Characterizaiton of Cuo Nano-Rod for Supercapacitor Applications

A novel approach solvothermal synthesis method has been utilized to prepare CuO nanorods for electrochemical capacitors. A new method of synthesis has been adopted for the synthesis of CuO nanostructures. Structural, morphological features of the prepared material were studied by XRD and SEM respectively. Electrochemical supercapacitive performances of the modified electrode material were also analyzed by electrochemical workstation in three-electrode system. This material found to exhibit pesudocapacitive behavior with high capacitance of 135.23 F/g at the prevalent density of 1 A/g in 1M Na2SO4 electrolyte solution, proving a suitable candidate electrode material for supercapacitor applications.

Syntheses and Characterizations of Supercapacitors Using Nano-Sized ZnO/Nanoporous Carbon Electrodes and PVA-Based Polymer-Hydrogel Electrolytes

Supercapacitors have been successfully fabricated using nano-sized ZnO/nanoporous carbon (nano-sized ZnO/NPC) electrodes and various hydrogel electrolytes. The nano-sized ZnO/NPC materials have been prepared from zinc acetate (Zn(CH3COO)2) and coconut shell using a simple heating method. Polyvinyl alcohol (PVA) hydrogel blended with phosphoric acid (H3PO4), lithium hydroxide (LiOH) and sodium sulfate (Na2SO4) electrolytes, respectively, has been located between the electrodes. Two of the nano-sized ZnO/NPC electrodes with area of 1 cm2 and those PVA hydrogel electrolytes were pressed together and annealed at 60 °C for 60 min. to construct the supercapacitors. It has been found that the supercapacitor with nano-sized ZnO/NPC electrodes and Na2SO4 electrolyte has the highest capacitance of 60.4 Fg-1.

PEMECAHAN (SPLITTING) MOLEKUL AIR MENJADI GAS H2DAN O2 MELALUI PROSES FOTOVOLTAIK

One method to overcome the scarcity of alternative sources of energy on earth is through the development of photovoltaic cells. This method used a solar energy to electrical energy transformation. In this research, breaking (splitting) of water molecules into H2 and O2 gas by the photovoltaic process uses electrodes CuO/C with Na2SO4 electrolyte. In this process used 2 photovoltaic cells as electricity producing and U-shaped electrolysis cell for solver (splitting) of water molecule produce H2 and O2 gas. CuO electrode (anode) is made through the burning of copper rod in a furnace at temperature 400 oC with a variety of combustion 1, 3, 4 times each lasting for 1 hs, while the cathode in the form of carbon rods obtained from 2B pencil. The optimum conditions for Na2SO4 electrolyte concentration is 0.8 N and for CuO electrodes with 3x burning. Optimum efficiency photovoltaic process was 2.66%. H2 and O2 gas volume obtained near stoichiometric ratio is 2 : 1.

PENARIKAN ION Cu2+ (CuSO4) DARI LARUTAN AIR MELALUI PROSES ELEKTROLISIS SECARA FOTOVOLTAIK DENGAN SEMIKONDUKTOR LAPISAN OKSIDA CuO DAN ZnO DARI KUNINGAN

Photovoltaic is a method that can convert sunlight energy into electrical energy. One use ofphotovoltaic electrolysis can be used for metal ions contained in the liquid waste. The research aims electrolyzing Cu2+ ions from aqueous solution using a series of photovoltaic cells with semiconductor CuO and ZnO oxide layer of brass with Na2SO4 electrolyte. The series of photovoltaic cells is associated with an electrolysis cell containing Cu2+ ions to be electrolysed. Semiconductor electrodes made with brass burning in a furnace in a few repetitions at a temperature of 400°C for 1 hour. U-shaped electrolysis cells glass tube containing a solution of CuSO4 1.25 g/L using a carbon rod as anode and cathode. Electrolysis of Cu2+ ions results were analyzed by Atomic Absorption Spectrofotometer (AAS). The results showed that the optimum conditions Na2SO4 electrolyte concentration 0.8 N with semiconductor double-furnace with a strong current 0.829 mA and a voltage of 0.241 mV, the value of efficiency of conversion of solar energy into electrical energy is 0.599%. Electrolysis of Cu2+ ions for 4 weeks could reduce Cu2+ ions concentration of 35 mg/L to 15.909 mg/L (45.45%). CuO and ZnO electrodes was relatively less stable and cause strong currents and voltage drop along the length of the process.