Penerapan Pembelajaran Berbasis Inquiry pada Materi Elektrokimia terhadap Pemahaman Konseptual, Model Mental dan Sikap Siswa

The purpose of this article review is to know the effect of applying inquiry-based learning on electrochemistry material to conceptual understanding, mental model and student attitudes. Based on some articles that have been reviewed, it can be concluded that the application of inquiry-based learning can improve conceptual understanding, mental model and positive attitude of students on electrochemistry material. The 5E inquiry (Engagement, Exploration, Explanation, Elaboration, and Evaluation) can be combined with the galvanic cell kit model to improve students' understanding of electrochemistry at the submicroscopic (molecular) level. Inquiry-based learning can be applied in both laboratory activities and classroom learning processes. The students' understanding of chemistry will be intact if students are able to connect the three levels of chemical representation.

Bio-electrochemical production of hydrogen and electricity from organic waste

This study investigated the performance of a novel integrated bio-electrochemical system for synergistic hydrogen production from a process combining a dark fermentation reactor and a galvanic cell. The operating principle of the system is based on the electrochemical conversion of protons released upon dissociation of the acid metabolites of the biological process and is mediated by the electron flow from the galvanic cell, coupling biochemical and electrochemical hydrogen production. Accordingly, the galvanic compartment also generates electricity. Four different experimental setups were designed to provide a preliminary assessment of the integrated bio-electrochemical process and identify the optimal configuration for further tests. Subsequently, dark fermentation of cheese whey was implemented both in a stand-alone biochemical reactor and in the integrated bio-electrochemical process. The integrated system achieved a hydrogen yield in the range 75.5 – 78.8 N LH2/kg TOC, showing a 3 times improvement over the biochemical process.

Electrodegradation of Acid Mixture Dye through the Employment of Cu/Fe Macro-Corrosion Galvanic Cell in Na2SO4 Synthetic Wastewater

Traditional wastewater purification processes are based on a combination of physical, chemical, and biological methods; however, typical electrochemical techniques for removing pollutants require large amounts of electrical energy. In this study, we report on a process of wastewater purification, through continuous anodic dissolution of iron anode for aerated Cu/Fe galvanic cell in synthetic Na2SO4 wastewater solution. Electrochemical experiments were conducted by means of a laboratory size electrolyzer, where electrocoagulation along with electrooxidation phenomena were examined for wastewater containing Acid Mixture dye. The above was visualized through the employment of electrochemical (cyclic voltammetry and ac impedance spectroscopy techniques) along with instrumental spectroscopy analyses.

Self-Powered Point-of-Care Device for Galvanic Cell-Based Sample Concentration Measurement

A novel self-powered point-of-care low-power electronics approach for galvanic cell-based sample concentration measurement is presented. The electronic system harvests and senses at the same time from the single cell. The system implements a solution that is suitable in those scenarios where extreme low power is generated from the fuel cell. The proposed approach implements a capacitive-based method to perform a non-linear sweep voltammetry to the cell, but without the need to implement a potentiostat amplifier for that purpose. It provides a digital-user readable result without the need for external non-self-powered devices or instruments compared with other solutions. The system conception was validated for a particular case. The scenario consisted of the measurement of a NaCl solution as the electrolyte, which was related to the conductivity of the sample. The electronic reader continuously measured the current with a transfer function gain of 1.012 V mA−1. The overall system exhibited a maximum coefficient of variation of 6.1%, which was an improvement compared with the state-of-the-art. The proof of concept of this electronics system was validated with a maximum power consumption of 5.8 μW using commercial-off-the-self parts.

Novel Quantum Gravity Model of the Physics of Operability of Galvanic Cells and Electrical Power Generation

The dimensions of the physical variables like resistance, electrical current and potential difference associated with ohm’s law have been evaluated applying the theory of quantum gravity (QG theory) and those dimensions have been utilized to evaluate the actual mechanism of functioning of the galvanic cells to originate electricity, power and power transmissions. Itself, the terminology, ‘Electromotive Force (emf) ‘of a galvanic cell does not stand at the proper stead, as has been established in this article by revealing the unidimensional characteristics of emf or the difference in electrode potential between the positive electrode (cathode) and the negative electrode (anode). In QG theory, Force is a 2-dimensional physical variable of the universe, being originated from unidimensional ‘Distance’ or ‘Entropy’. The traditional concept of the mapping the emf of galvanic cells by the free energy changes of the chemical reaction occurring in a cell is not justified and the energy output from a galvanic cell has been proved to be a phenomenon of continuous passage or flow of in-situ activation volumes or activation energies of the chemical reactions occurring, through the external conducting paths.