Understanding Of Electrochemistry Research Articles

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.

Electrochemical Deconstruction Along with Spectroscopic Investigations of Electroactive Heme Proteins and Enzymes

The iron – porphyrin system, known in biology as heme, is ubiquitous in the chemistry of modern living systems. Heme forms the active site for a large class of biologically relevant molecules including proteins and enzymes like hemoglobin, myoglobin, cytochromes etc. Heme based molecules perform a host of biochemical functions out of which redox homeostasis (controlled by cytochromes) and oxygen storage and transport (controlled by hemoglobin / myoglobin) are some of the most important features. Some of these molecules also serve as good biomarkers for different types of physico-chemical stress on organisms. It is well known that the functionality of these heme based proteins / enzymes is carefully modulated by the oxidation state of iron at the active site. Hence, it is important to understand the redox chemistry of iron in these systems in order to understand their biochemical functions more elaborately. Our studies are directed towards a set of heme biomolecules and a few simple iron – porphyrin analogues. We examine the electrochemistry of heme proteins / enzymes and compare them with the electrochemistry of iron – porphyrin complexes. It is mainly the local electronic structure around the active site (primarily the coordination of iron), that controls the redox behaviour of the Fe III/II couple. We try to rationalize changes in the iron redox electrochemistry in terms of local coordination of amino acids to the iron center. With a set of amino acids, we are able to identify a few simple interactions which control redox reversibility of iron in these systems. We use simple electronic structure theory calculations to validate the claims made from electrochemistry data. We believe that an elaboration of the amino acid interaction database to include all known amino acids would per se allow us to predict the electrochemistry of any sequenced heme protein / enzyme, as well as design heme proteins/enzymes de novo with tailored electrochemical properties. Having understood the nature of the molecular interactions that control redox reversibility of iron in heme systems, we attempt to utilize this in the development of efficient electrochemical sensors for these systems. Confining the molecule on a nanodimensional host on the electrode surface enhances the electrochemical response of the molecule – an ideal situation for use in a biosensor. We investigate this in terms of change in dynamics and active site electronic structure of the protein under confinement. From the point of view of local as well as global dynamics, neutron scattering indicates an ordered diffusion and restriction of peptide backbone fluctuation under confinement. Active site electronic structure, as studied through X ray absorption spectroscopy, indicates minor changes in the local coordination geometry under confinement, presumably due to surface interactions, while long ranges ordering remains unchanged. We use a simple in operando experiment to look at the evolution of electronic structure of the active site with electrochemical cycling. Overall, we identify molecular interactions around the iron active site in heme systems that control the electrochemical response, attempt to design a confinement based sensor model for heme, and use a host of spectroscopic techniques to identify changes in electronic structure and protein dynamics that make the sensor work efficiently. These studies substantially enrich our understanding of electrochemistry as well as fundamental physical biochemistry of heme enzymes and proteins.

Facilitating Conceptual Change in Students' Comprehension of Electrochemistry Concepts through Collaborative Teaching Strategy

This paper reports on a study to determine the effectiveness of collaborative teaching on physical sciences students' comprehension of electrochemistry in the Ximhungwe circuit of the Bohlabela district in the Mpumalanga province of South Africa. The design of the teaching strategy draws upon theoretical insights into perspectives of social constructivism and empirical studies to improve upon the teaching of the main topic, specifically galvanic cells, electrolytic cells and electrode potentials. In addition, the effect of collaboration as a teaching strategy on students’ perception of their chemistry classroom environment was also investigated. A sample of 90 grade 12 physical sciences students from four intact public schools was conveniently selected to participate in the study. Students were given electrochemistry concept test (ECT) as well as chemistry classroom environment questionnaire (CCEQ) as pre-test and post-test. One-way analysis of covariance (ANCOVA) conducted showed that students taught using collaboration had significantly better acquisition of scientific conceptions related to electrochemistry than students taught using lecture method. Pearson Product-Moment Correlation also revealed that there was a significant positive relationship between achievement and students’ perception of their chemistry classroom environment. However, ANCOVA and ANOVA results indicated that there was no significant contribution of students’ perception of their chemistry classroom environment to their comprehension of electrochemistry concepts. This study provides statistical evidence on the importance of meaningful learning combined with social process to improve students’ understanding of electrochemistry.

How neutrons as a probe for in situ and in operando measurements support the understanding of electrochemistry in Li-ion battery research

How neutrons as a probe for in situ and in operando measurements support the understanding of electrochemistry in Li-ion battery research

Unveiling Microscopic Structures of Charged Water Interfaces by Surface-Specific Vibrational Spectroscopy.

A sum-frequency spectroscopy scheme is developed that allows the measurement of vibrational spectra of the interfacial molecular structure of charged water interfaces. The application of this scheme to a prototype lipid-aqueous interface as a demonstration reveals an interfacial hydrogen-bonding water layer structure that responds sensitively to the charge state of the lipid headgroup and its interaction with specific ions. This novel technique provides unique opportunities to search for better understanding of electrochemistry and biological aqueous interfaces at a deeper molecular level.

Electrochemical sensing and biosensing based on square wave voltammetry

Square wave voltammetry (SWV) has been widely used in the development of electrochemical sensors and biosensors in recent years due to its high selectivity and sensitivity. It is of great interest and importance to rapidly and sensitively detect disease-related biomarkers, environmental pollutants (e.g., heavy metals and other chemical contaminants), which are severely detrimental to human and animal life and the environment as a whole. Further, efficacious sensing is required for the detection of food resident contaminants (e.g., bacteria, viruses and parasites) and for the verification of the therapeutic ingredients of dietary supplements. Enzyme kinetics is another interesting domain that employs SWV as an effective analytical tool for the mechanistic study of enzyme reactions. The aim of this paper is to provide a comprehensive review of the electrochemical SWV method and its significant applications in sensing and biosensing spanning various fields such as diagnosis, environmental and food analysis and enzyme kinetics. The development of novel and improved electrode surfaces and nanomaterials introduces the possibility of sensors and biosensors that will exhibit even higher sensitivity, with SWV serving as an ideal methodology for its optimization. Concurrent with a better understanding of electrochemistry and life sciences, sensors and biosensors based on SWV have the potential to serve as next generation point-of-care diagnostic devices, as well as highly sensitive and selective detectors for food/environmental monitoring and enzyme studies.

Inquiry-Based Laboratory Activities in Electrochemistry: High School Students’ Achievements and Attitudes

This study aimed to investigate the effects of inquiry-based laboratory activities on high school students’ understanding of electrochemistry and attitudes towards chemistry and laboratory work. The participants were 62 high school students (average age 17 years) in an urban public high school in Turkey. Students were assigned to experimental (N = 30) and control groups (N = 32). The experimental group was taught using inquiry-based laboratory activities developed by the researchers and the control group was instructed using traditional laboratory activities. The results of the study indicated that instruction based on inquiry-based laboratory activities caused a significantly better acquisition of scientific concepts related to electrochemistry, and produced significantly higher positive attitudes towards chemistry and laboratory. In the light of the findings, it is suggested that inquiry-based laboratory activities should be developed and applied to promote students’ understanding in chemistry subjects and to improve their positive attitudes.

Understanding the Surface Potential of Water

We have resolved the inconsistency in quantifying the surface potential at the liquid-vapor interface when using explicit ab initio electronic charge density and effective atomic partial charge models of liquid water. This is related, in part, to the fact that the resulting electric potentials from partial-charge models and ab initio charge distributions are quite different except for those regions of space between the molecules. We show that the electrostatic surface potential from a quantum mechanical charge distribution compares well to high-energy electron diffraction and electron holography measurements, as opposed to the comparison with electrochemical measurements. We suggest that certain regions of space be excluded when comparing computed surface potentials with electrochemical measurements. This work describes a novel interpretation of ab initio computed surface potentials through high-energy electron holography measurements as useful benchmarks toward a better understanding of electrochemistry.

Effects of jigsaw and animation techniques on students’ understanding of concepts and subjects in electrochemistry

This study investigated the effect of jigsaw cooperative learning and animation versus traditional teaching methods on students’ understanding of electrochemistry in a first-year general chemistry course. This study was carried out in three different classes in the department of primary science education during the 2007–2008 academic year. The first class was randomly assigned as the jigsaw group, the second as the animation group, and the third as the control group. Students participating in the jigsaw group were divided into five “home groups” since the topic electrochemistry is divided into five subtopics. Each of these home groups contained four students. The groups were as follows: (1) Home Group A (HGA), representing the fundamental concepts of electrochemistry, (2) Home Group B (HGB), representing the electrochemical cell and energy source, (3) Home Group C (HGC), representing electrolysis, (4) Home Group D (HGD), representing Faraday’s laws, and (5) Home Group E (HGE), representing corrosion. The home groups broke apart, like pieces of a jigsaw puzzle, and the students moved into jigsaw groups consisting of members from the other home groups, who were each assigned a subtopic. For students in the animation group, their lesson focused on explaining the step-by-step process of electrochemistry through a computer-animated presentation. The main data collection tools were the Test of Scientific Reasoning and the Particulate Nature of Matter Evaluation Test. The results indicated that the jigsaw and animation groups achieved better results than the control group.

Effect of Cooperative Learning Strategies on Students' Understanding of Concepts in Electrochemistry

The present study was conducted to investigate the degree of effectiveness of cooperative learning instruction over a traditional approach on 11th grade students' understanding of electrochemistry. The study involved forty-one 11th grade students from two science classes with the same teacher. To determine students' misconceptions concerning electrochemistry, the Electrochemistry Concept Test consisting of 8 open-ended and 12 multiple-choice questions was used as a pre-test and some students were interviewed. According to the results, twenty-four misconceptions (six of them initially identified) about electrochemistry were identified. The classrooms were randomly assigned to a control group (traditional instruction, 21 students) and an experimental group (cooperative learning based on a constructivist approach, 20 students). After instruction, the same test was administered to both groups as a post-test. The results from the t-test indicated that the students who were trained using cooperative learning instruction had significantly higher scores in terms of achievement than those taught by the traditional approach. According to the post-test and interviews, it was also found that instruction for the cooperative group was more successful in remediation of the predetermined misconceptions.

A Conceptual Change Teaching Strategy to Facilitate High School Students' Understanding of Electrochemistry

Recent research in chemistry education has shown an increasing interest in the facilitation of conceptual change in student understanding of chemical concepts. Most of the studies have tried to show the difference in student performance on algorithmic and conceptual problems. The objective of this study is to go beyond and design a teaching strategy based on two “teaching experiments” that could facilitate students' conceptual understanding of electrochemistry. The study is based on two sections (control, n = 29; experimental, n = 28) of 10th grade high school students at a public school in Venezuela. Experimental group participated in two teaching experiments designed to generate situations/experiences in which students are forced to grapple with alternative responses leading to cognitive conflicts/contradictions. Results obtained show that learning electrochemistry involves both algorithmic and conceptual problems. On Posttest 1, 93% of the experimental group students responded correctly, in contrast to 39% of the control group. On Posttest 2, 39% of the experimental group responded correctly, in contrast to 0% of the Control group. The difference in performance on both posttests is statistically significant (p < 0.001). It is concluded that the “teaching experiments” facilitated students' understanding (progressive transitions) of electrochemistry.

Facilitating conceptual change in students' understanding of electrochemistry

The main objective of this study is to construct a teaching strategy that can facilitate conceptual change in freshman students' understanding of electrochemistry. A major premise of the study is that providing students with the correct response along with alternative responses (teaching experiments) provides a conflicting situation that is conducive towards an equilibration of their cognitive structures. Students in the Experimental group participated in two 'teaching experiments', whereas those in the Control group solved similar problems without the experimental format. Results obtained show that the difference in performance of the experimental and control groups on post-tests 1 and 2 was statistically significant. It is concluded that the 'teaching experiments' facilitated students' understanding of electrochemistry.

Conceptual difficulties experienced by senior high school students of electrochemistry: Electrochemical (galvanic) and electrolytic cells

AbstractThis research investigated students' understanding of electrochemistry following a 7–9‐week course of instruction. A list of conceptual and propositional knowledge statements was formulated, and this provided the framework for semistructured interviews that were conducted with 32 students in their final year of high school chemistry, following instruction in electrochemistry. Three misconceptions identified in this study and five which have been reported earlier are incorporated into an alternative framework about electric current. The framework is grounded on the notion that a current always involves drifting electrons, even in solution. Another area where students' misconceptions were prevalent was in relation to the sign of the anode and cathode. Students who thought the anode was negatively charged believed cations would move toward it, and those who thought it was positively charged were unable to explain why electrons move away from it. Electrolytic cells also proved troublesome for students. Many students did not associate the positions of the anode and cathode with the polarity of the applied electromotive force (e.m.f.). Other students attempted to reverse features of electrochemical cells and apply the reversals to electrolytic cells. The implications of the research relate to students' interpretation of the language that is used to describe scientific phenomena and the tendency for students to overgeneralize, due to comments made by teachers or statements in textbooks.

Conceptual difficulties experienced by senior high school students of electrochemistry: Electric circuits and oxidation‐reduction equations

AbstractThe purpose of this research was to investigate students' understanding of electrochemistry following a course of instruction. A list of conceptual and propositional knowledge statements was formulated to identify the knowledge base necessary for students to understand electric circuits and oxidation‐reduction equations. The conceptual and propositional knowledge statements provided the framework for the development of a semistructured interview protocol which was administered to 32 students in their final year of high school chemistry. The interview questions about electric circuits revealed that several students in the sample were confused about the nature of electric current both in metallic conductors and in electrolytes. Students studying both physics and chemistry were more confused about current flow in metallic conductors than students who were only studying chemistry. In the section of the interview which focused on oxidation and reduction, many students experienced problems in identifying oxidation‐reduction equations. Several misconceptions relating to the inappropriate use of definitions of oxidation and reduction were identified. The data illustrate how students attempted to make sense of the concepts of electrochemistry with the knowledge they had already developed or constructed. The implications of the research are that teachers, curriculum developers, and textbook writers, if they are to minimize potential misconceptions, need to be cognizant of the relationship between physics and chemistry teaching, of the need to test for erroneous preconceptions about current before teaching about electrochemical (galvanic) and electrolytic cells, and of the difficulties experienced by students when using more than one model to explain scientific phenomena.