Ibrahim Khan

Bio: Ibrahim Khan is an academic researcher from King Fahd University of Petroleum and Minerals. The author has contributed to research in topics: Water splitting & Band gap. The author has an hindex of 26, co-authored 92 publications receiving 2951 citations. Previous affiliations of Ibrahim Khan include University of Illinois at Urbana–Champaign & University of Peshawar.

Review on Methylene Blue: Its Properties, Uses, Toxicity and Photodegradation

Abstract: The unavailability of clean drinking water is one of the significant health issues in modern times. Industrial dyes are one of the dominant chemicals that make water unfit for drinking. Among these dyes, methylene blue (MB) is toxic, carcinogenic, and non-biodegradable and can cause a severe threat to human health and environmental safety. It is usually released in natural water sources, which becomes a health threat to human beings and living organisms. Hence, there is a need to develop an environmentally friendly, efficient technology for removing MB from wastewater. Photodegradation is an advanced oxidation process widely used for MB removal. It has the advantages of complete mineralization of dye into simple and nontoxic species with the potential to decrease the processing cost. This review provides a tutorial basis for the readers working in the dye degradation research area. We not only covered the basic principles of the process but also provided a wide range of previously published work on advanced photocatalytic systems (single-component and multi-component photocatalysts). Our study has focused on critical parameters that can affect the photodegradation rate of MB, such as photocatalyst type and loading, irradiation reaction time, pH of reaction media, initial concentration of dye, radical scavengers and oxidising agents. The photodegradation mechanism, reaction pathways, intermediate products, and final products of MB are also summarized. An overview of the future perspectives to utilize MB at an industrial scale is also provided. This paper identifies strategies for the development of effective MB photodegradation systems.

Nanomaterial-based optical chemical sensors for the detection of heavy metals in water: Recent advances and challenges

Abstract: The anthropogenic release of heavy metals into the natural water has become a global epidemic. Heavy metal contamination poses serious threats to human health and the environment. Therefore, the development of sensors for monitoring of these toxic metals in different matrices, especially in water, is very important. As a powerful analytical tool, nanomaterial-based chemical sensors have been extensively employed for the detection of heavy metals. These nanosensors offer several advantages including high sensitivity, selectivity, portability, on-site detection ability and improved performance of devices. Moreover, the deployment of molecular recognition probe on the nanostructures for the selective binding have enhanced the selectivity and detection ability. In this review, we critically engross on the recent progress in the design of nanomaterial-based sensors for the detection of heavy metals using various sensing strategies. The optical sensors focused and discussed in the review include fluorescent, surface enhanced Raman scattering and surface plasmon resonance sensors.

COVID-19 pandemic and its positive impacts on environment: an updated review.

Abstract: In December, 2019 in Wuhan city of China, a novel coronavirus (SARS-CoV-2) has garnered global attention due to its rapid transmission. World Health Organization (WHO) termed the infection as Coronavirus Disease 2019 (COVID-19) after phylogenic studies with SARS-CoV. The virus causes severe respiratory infections with dry cough, high fever, body ache and fatigue. The virus is primarily transmitted among people through respiratory droplets from COVID-19 infected person. WHO declared this COVID-19 outbreak a pandemic and since February, 2020 affected countries have locked down their cities, industries and restricted the movement of their citizens to minimize the spread of the virus. In spite of the negative aspects of coronavirus on the globe, the coronavirus crises brought a positive impact on the natural environment. Countries where the movement of citizens was seized to stop the spread of coronavirus infection have experienced a noticeable decline in pollution and greenhouse gases emission. Recent research also indicated that this COVID-19-induced lockdown has reduced the environmental pollution drastically worldwide. In this review, we have discussed some important positive impacts of coronavirus on environmental quality by compiling the recently published data from research articles, NASA (National Aeronautics and Space Administration) and ESA (European Space Agency).

Two-Dimensional Nanostructured Materials for Gas Sensing

Abstract: Two-dimensional (2D) nanostructures are highly attractive for fabricating nanodevices due to their high surface-to-volume ratio and good compatibility with device design. In recent years 2D nanostructures of various materials including metal oxides, graphene, metal dichalcogenides, phosphorene, BN and MXenes, have demonstrated significant potential for gas sensors. This review aims to provide the most recent advancements in utilization of various 2D nanomaterials for gas sensing. The common methods for the preparation of 2D nanostructures are briefly summarized first. The focus is then placed on the sensing performances provided by devices integrating 2D nanostructures. Strategies for optimizing the sensing features are also discussed. By combining both the experimental results and the theoretical studies available, structure-properties correlations are discussed. The conclusion gives some perspectives on the open challenges and future prospects for engineering advanced 2D nanostructures for high-performance gas sensors devices.

Superconcentrated Electrolytes for a High-Voltage Lithium-Ion Battery

Abstract: Finding a viable electrolyte for next-generation 5 V-class lithium-ion batteries is of primary importance. A long-standing obstacle has been metal-ion dissolution at high voltages. The LiPF6 salt in conventional electrolytes is chemically unstable, which accelerates transition metal dissolution of the electrode material, yet beneficially suppresses oxidative dissolution of the aluminium current collector; replacing LiPF6 with more stable lithium salts may diminish transition metal dissolution but unfortunately encounters severe aluminium oxidation. Here we report an electrolyte design that can solve this dilemma. By mixing a stable lithium salt LiN(SO2F)2 with dimethyl carbonate solvent at extremely high concentrations, we obtain an unusual liquid showing a three-dimensional network of anions and solvent molecules that coordinate strongly to Li(+) ions. This simple formulation of superconcentrated LiN(SO2F)2/dimethyl carbonate electrolyte inhibits the dissolution of both aluminium and transition metal at around 5 V, and realizes a high-voltage LiNi0.5Mn1.5O4/graphite battery that exhibits excellent cycling durability, high rate capability and enhanced safety.

Health Impact of Silver Nanoparticles: A Review of the Biodistribution and Toxicity Following Various Routes of Exposure

Abstract: Engineered nanomaterials (ENMs) have gained huge importance in technological advancements over the past few years. Among the various ENMs, silver nanoparticles (AgNPs) have become one of the most explored nanotechnology-derived nanostructures and have been intensively investigated for their unique physicochemical properties. The widespread commercial and biomedical application of nanosilver include its use as a catalyst and an optical receptor in cosmetics, electronics and textile engineering, as a bactericidal agent, and in wound dressings, surgical instruments, and disinfectants. This, in turn, has increased the potential for interactions of AgNPs with terrestrial and aquatic environments, as well as potential exposure and toxicity to human health. In the present review, after giving an overview of ENMs, we discuss the current advances on the physiochemical properties of AgNPs with specific emphasis on biodistribution and both in vitro and in vivo toxicity following various routes of exposure. Most in vitro studies have demonstrated the size-, dose- and coating-dependent cellular uptake of AgNPs. Following NPs exposure, in vivo biodistribution studies have reported Ag accumulation and toxicity to local as well as distant organs. Though there has been an increase in the number of studies in this area, more investigations are required to understand the mechanisms of toxicity following various modes of exposure to AgNPs.

Polymeric nanoparticles: production, characterization, toxicology and ecotoxicology

Abstract: Polymeric nanoparticles (NPs) are particles within the size range from 1 to 1000 nm and can be loaded with active compounds entrapped within or surface-adsorbed onto the polymeric core. The term “nanoparticle” stands for both nanocapsules and nanospheres, which are distinguished by the morphological structure. Polymeric NPs have shown great potential for targeted delivery of drugs for the treatment of several diseases. In this review, we discuss the most commonly used methods for the production and characterization of polymeric NPs, the association efficiency of the active compound to the polymeric core, and the in vitro release mechanisms. As the safety of nanoparticles is a high priority, we also discuss the toxicology and ecotoxicology of nanoparticles to humans and to the environment.