Tahira Mahmood

By Tahira Mahmood, Madeeha Aslam and Abdul Naeem

Global energy shortage will be one of the most critical challenges in the next 50 years. Currently, over 80% of energy consumed is produced from fossil fuels, which is directly linked to global warming and environmental pollution issues. Environment-friendly renewable energy is rapidly gaining importance for the existence of human civilization. A leading source of renewable energy is the solar energy, which is inexhaustible and abundantly available. Solar cells that convert solar energy directly into electricity are drawing considerable attention as a potential turnkey solution to address these challenges. Several approaches have been made in this respect, including the development of better materials and the designs of new solar cell configuration and architecture. Among the innovative materials with potential application in emerging 3G solar cells, graphene and its derivatives such as GO, rGO and G/nanocomposite have been widely explored as transparent conducting electrodes, electron donor or acceptor materials and counter electrodes (CE). In this chapter, the use of graphene nanocomposites has been explored as an electrode material in DSSCs and PSCs. Recently, graphene/metal oxide nanocomposites have been widely used in DSSCs and PSCs and played a significant role in increasing charge transport, reducing charge recombination and thus enhancing the performance of solar cell.

Part of the book: Assorted Dimensional Reconfigurable Materials

By Madeeha Aslam, Tahira Mahmood and Abdul Naeem

Organic-inorganic perovskite materials, due to the simultaneous possession of various properties like optical, electronic and magnetic beside with their structural tunability and good processability, has concerned the attention of researchers from the field of science and technology since long back. Recently, the emergence of efficient solar cells based on organic-inorganic perovskite absorbers promises to alter the fields of thin film, dye-sensitized and organic solar cells. Solution processed photovoltaics based on organic-inorganic perovskite absorbers CH3NH3PbI3 have attained efficiencies of over 25%. The increase in popularity and considerable enhancement in the efficiency of perovskites since their discovery in 2009 is determined by over 6000 publications in 2018. However, although there are broad development prospects for perovskite solar cells (PSCs), but the use of CH3NH3PbI3 results in lead toxicity and instability which limit their application. Therefore, the development of environmental-friendly, stable and efficient perovskite materials for future photovoltaic applications has long-term practical significance, which can eventually be commercialized.

Part of the book: Perovskite and Piezoelectric Materials

By Tahira Mahmood, Abid Ullah and Rahmat Ali

Nanotechnologies and nanocomposite materials have gained the attention of scientific community in recent years. Nanocomposite material consists of several phases where at least one, two, or three dimensions are in the nanometer range. Nanocomposites with advanced carbon nanostructures i.e., carbon nanotube (CNTs) and graphene, attachments have been regarded as promising prospects. CNTs and graphene-based improved nanocomposites are usually categorized into various classes based on different types of discontinues phases. The nanocomposites reinforced with carbon nanomaterials i.e., CNTs and graphene have been explored extensively for use as engineering materials in several demanding applications because of their excellent properties. The present book chapter has been prepared in three main sections. In the first portion, nanocomposites and carbon nanofillers i.e., CNTS and graphene have been presented. In the second part, different types of CNTs and graphene-based improved nanocomposites have been described with reported literature. In the third section, focus is on the applications of improved nanocomposites such as energy storage, antimicrobial activity, gene delivery, catalyzed organic reactions, radar adsorbing materials, actuators, wind turbine blades, pollutant removal, aerospace industry, and conductive plastics.

Part of the book: Nanocomposite Materials for Biomedical and Energy Storage Applications

By Tahira Mahmood, Saima Momin, Rahmat Ali, Abdul Naeem and Afsar Khan

Emerging contaminants (ECs) include both natural and man-made compounds that have recently been found to be present in wastewater and have a harmful effect on human health and aquatic environment. Several ECs such as pharmaceuticals, antibacterial, hormones, synthetic dyes, flame retardants are directly or indirectly discharged from hospitals, agricultural, industrial and other sources to the environment. Strategies have been developed to overcome the challenges faced by contaminated water treatment technologists. Advanced treatment technologies such as physical, chemical, and biological methods have been studied for ECs removal as well as for reduction of effluents levels in discharged water. Techniques such as membrane filtration, adsorption, coagulation-flocculation, solvent extraction, ion exchange, photodegradation, catalytic oxidation, electrochemical oxidation, ozonation and precipitation, etc., have been investigated. Based on past research, these techniques significantly remove one or more pollutants but are insufficient to remove most of the toxic contaminants efficiently from wastewater. Nanomaterial incorporated technologies may be a proficient approach for removing different contaminants from wastewater. These technologies are costly because of high-energy consumption during the treatment of wastewater for reuse on large scale. Consequently, comprehensive research for the improvement of wastewater treatment techniques is required to obtain complete and enhanced EC removal by wastewater treatment plants.

Part of the book: Wastewater Treatment

By Tahira Mahmood, Rahmat Ali, Abdul Naeem and Murtaza Syed

Microencapsulated phase change materials have been considered as potential candidates to overcome the global energy shortage, as these materials can provide a viable method for storing thermal energy and offering consistent energy management by controllable heat release in desirable environments. Microencapsulation technology offers a method for overcoming the trouble associated with the handling of solid–liquid phase change materials (PCMs) via encapsulating PCMs with thin or tiny shells which are known as ‘microcapsules’. Microcapsule shells not only keep PCMs isolated from the surrounding materials but also provide a stable structure and sufficient surface for PCMs to enhance heat transfer. Thus microencapsulation technology received remarkable attention from fundamental studies to industrial growth in recent years. In order to provide a reliable source of information on recent progress and development in microencapsulated PCMs, this chapter emphases on methods and techniques for the encapsulation of PCMs with a diversity of shell materials from traditional organic polymers to novel inorganic materials to pursue high encapsulation efficiency, excellent thermal energy-storage performance and long-term operation durability. The chapter also highlights the design of bi- and multi-functional PCM-based microcapsules by fabricating various functional shells in a multilayered structure to meet the growing demand for versatile applications.

Part of the book: Nanocomposite Materials for Biomedical and Energy Storage Applications