Progress on perovskite materials for energy application

Energy underlies the human development and welfare. Today energy depends on combustion of fossil fuels (coal, natural gas, oil) sources. These sources have not only led to severe environmental issues because it emits greenhouse gases, they are rapidly depleted due to their enormous consumption. For several years’ numerous technologies have been developed to address the fossil fuel depletion and greenhouse gases emission from the non-renewable in order to constantly supply energy to the people and industries. However, the challenge of being able to store energy generated and utilize it later is a matter of importance when resolving energy problems persists. New materials, particularly perovskites offer a great advantage to be utilized as a possible host or carriers for energy applications. The impact of defect on the material properties and influence of defects as material for energy application is described. The use of perovskites oxides for effective electrocatalysis in hydrogen evolution reactions, photocataysis, photovoltaic solar cells, electrocatalysis, solid oxide fuel cells, supercapacitors and metal-air batteries, are also included. This review covers the latest progress on perovskite oxides as electrochemical energy materials

Instrumental techniques for characterization of molybdenum disulphide nanostructures

The excellent chemical and physical properties of materials (nanomaterials) with dimensions of less than 100 nm (nanometers) resulted in researchers and industrialists to have great interest in their discovery and applications in various systems/applications. As their sizes are reduced to nanoscale, these nanomaterials tend to possess exceptional properties differing from those of their bulk counterparts; hence, they have found applications in electronics and medicines. In order to apply them in those applications, there is a need to synthesise these nanomaterials and study their structural, optical, and electrochemical properties. Among several nanomaterials, molybdenum disulphide (MoS2) has received a great interest in energy applications due to its exceptional properties such as stability, conductivity, and catalytic activities. Hence, the great challenge lies in finding the state-of-the-art characterization techniques to reveal the different properties of MoS2 nanostructures with great accuracy. In this regard, there is a need to study and employ several techniques to accurately study the surface chemistry and physics of the MoS2 nanostructures. Hence, this review will comprehensively discuss a detailed literature survey on analytical techniques that can be used to study the chemical, physical, and surface properties of MoS2 nanostructures, namely, ultraviolet-visible spectroscopy (UV-vis), photoluminescence spectroscopy (PL), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, time-of-flight secondary ion mass spectroscopy (TOF-SIMS), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning and transmission electron microscopies (SEM and TEM), atomic force microscopy (AFM), energy dispersive X-ray spectroscopy (EDS/X), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and electroanalytical methods which include linear sweep (LSV) and cyclic (CV) voltammetry and electrochemical impedance spectroscopy (EIS)

Polyaniline-Based Nanocomposites for Environmental Remediation

With growth in civilisation and industrialisation, there is an increase in the release of toxic heavy metal ions and dyes into water system, which is of public concern. As a result, appropriate treatment methods have to be implemented in order to mitigate and prevent water pollution. The discovery of nanotechnology has led to the development and utilisation of various nanoadsorbent for the removal of pollutants from water. PANI nanostructures and nanocomposites are noble adsorbents that have gained popularity in addressing water pollution issues and have been reported in literature. In this chapter, the main focus is on the synthesis of PANI nanocomposites and nanostructures and their application as efficient adsorbents for water treatment. Detailed discussions on different synthetic routes and characterisation have been dedicated to applications of these materials and are compared for the adsorptive removal of heavy metal ions and dyes from water

Information and knowledge management in South African law firms - a case study

Thesis (MPhil)--Stellenbosch University, 2017.ENGLISH SUMMARY : This thesis investigates and analyse information and knowledge management systems in a typical large high performing law firm with multiple offices across the African continent. The intended outcome is to draw a full understanding of the lawyers’ interactions with the Information and Knowledge Management (IKM) systems in place and with each other, and any hindrances that may affect these interactions, information flows, knowledge transfer, and overall firm performance. Multinational organizations are complex in nature and have complex operational dynamics as opposed to organizations operating in one country. These dynamics range from issues related to administration and management, coordinated information sharing and knowledge transfer, information technologies and information systems, etc. all of which can be affected positively or negatively by a variety of factors such as distance, language, internet speed, culture, to name just a few. This becomes more so for law firms, multinational law firms in particular, which are the focus of this study. Being information intensive organizations by nature whose sole service offering is legal advice based on quality information and knowledge make such law firms more complex, and therefore a suitable subject of study for this thesis. The thesis concludes that, like all multinational organizations, multinational law firms face similar problems that hinder efficient and effective communication, information flows and knowledge sharing. That if not correctly addressed and managed, these problems can render IKM efforts and initiatives in law firms ineffective.AFRIKAANSE OPSOMMING : In hierdie tesis word die inligting- en kennisbestuurstelsels van ‘n tipiese groot, suksesgedrewe, Afrika-wye prokureursfirma ondersoek. Die doel van die studie is om prokureurs se interaksie met mekaar en met die inligting- en kennisbestuurstelsels (KBS) te begryp, asook die faktore wat hierdie omgang mag belemmer. Anders as nasionale organisasies is multi-nasionale organisasies komplekse stelsels met komplekse operasionele dinamika. Laasgenoemde sluit in administratiewe en bestuursdinamika, gekoördineerde inligtingverspreiding- en kennisoordragprosesse, en inligtingstegnologiee en -stelsels. Faktore soos afstand, taal, Internetspoed en kultuur, om net `n paar te noem, kan die dinamika beinvloed. Dit is veral relevant vir prokureursfirmas – veral multi-nasionale prokureursfirmas – wat die onderwerp van hierdie verhandeling is. Inligtingsensitiewe prokureursfirmas se uitsluitlike doel is om regsdienste te lewer gebaseer op kwaliteit inligting en kennis. Dit maak prokureursfirmas kompleks, en dus `n geskikte onderwerp vir hierdie verhandeling. In die tesis word die slotsom bereik dat multi-nasionale prokureursfirmas soortgelyke probleme as ander multi-nasionale organisasies ervaar. Hierdie probleme kan doeltreffende en effektiewe kommunikasie, die vloei van inligting en kennisoordrag belemmer. As hierdie uitdagings nie aangespreek en bestuur word nie, kan dit die prokureursfirma se KBSinisiatiewe oneffektief laat

Poly(3-aminobenzoic acid) Decorated with Cobalt Zeolitic Benzimidazolate Framework for Electrochemical Production of Clean Hydrogen

A novel composite of poly(3-aminobenzoic acid) (PABA) and a cobalt zeolitic benzimidazolate framework (CoZIF) has been studied for the production of hydrogen through the hydrogen evolution reaction (HER). The structural characteristics and successful synthesis of PABA, CoZIF and the PABA/CoZIF composite were confirmed and investigated using different techniques. Probing-ray diffraction for phase analysis revealed that the composite showed a decrease and shift in peak intensities, confirming the incorporation of CoZIF on the PABA backbone via in situ polymerization, with an improvement in the crystalline phase of the polymer. The thermal stability of PABA was enhanced upon composite formation. Both scanning electron microscopy and transmission electron microscopy showed that the composite had a rough surface, owing to an interaction between the CoZIF and the external surface of the PABA. The electrochemical hydrogen evolution reaction (HER) performance of the synthesized samples was evaluated using cyclic voltammetry and Tafel analysis. The composite possessed a Tafel slope value of 156 mV/dec and an α of 0.38, suggesting that the Volmer reaction coupled with either the Heyrovsky or Tafel reaction as the rate determining step. The fabricated composite showed high thermal stability and excellent tolerance as well as high electroactivity towards the HER, showing it to be a promising non-noble electrocatalyst to replace Pt-based catalysts for hydrogen generation