Muhammad Azam Qamar

Perovskite solar cells (PSCs) have revolutionized photovoltaics thanks to their tunable bandgaps and high power‐conversion efficiencies. Wide‐bandgap PSCs (WBG PSCs) are key candidates for high‐efficiency tandem photovoltaics, offering tunable bandgaps and the potential to surpass the Shockley–Queisser limit. However, practical deployment is hindered by defect‐mediated nonradiative recombination, phase instability, halide migration, and environmental degradation. This review systematically examines the integration of two‐dimensional (2D) materials to address these challenges, emphasizing defect passivation, charge‐carrier management, and interfacial engineering. Advances in inverted PSC architectures, including crystallization dynamics, passivation strategies, and interlayer design for selective charge transfer, are analyzed. Scalable fabrication methods such as vacuum deposition, one‐ and two‐step solution routes, and epitaxial growth are evaluated for their impact on device performance, reproducibility, and upscaling. Applications of 2D‐enhanced PSCs are surveyed, covering artificial indoor lighting, economic and environmental considerations, and integration into tandem solar cells with narrow‐ and wide‐bandgap components. Particular attention is given to front cells for WBG perovskites, interfacial engineering in all‐inorganic systems, and strategies to suppress deep‐level traps and ion migration. Finally, future research directions are discussed, highlighting the design of stable 2D/interface layers to achieve durable, high‐performance WBG inverted PSCs.

Graphene oxide, a 2D nanomaterial, has attracted significant attention for biomedical applications due to its exceptional properties, including tunable surface chemistry, excellent dispersibility, and abundant oxygen-containing functional groups that facilitate facile modification. Recent advancements in the synthesis and functionalization of graphene oxide-based materials have addressed their limitations, such as poor solubility and cytotoxicity, thereby making them safer and more effective for biomedical applications. This paper thoroughly outlines the structural attributes and principal qualities of graphene oxide-based materials, highlighting their mechanical strength, thermal stability, impermeability, electrical conductivity, and biological properties. Emerging developments in graphene oxide-based nanocomposites for fluorescence imaging, magnetic resonance imaging, photoacoustic imaging, Raman spectroscopy imaging, and multifunctional therapeutic platforms are thoroughly examined. Their effectiveness in biomedical scaffolds, wound-healing systems, controlled drug-release platforms, and antimicrobial coatings has been highlighted. Notwithstanding considerable advancements, issues related to cytotoxicity, biodegradability, long-term biosafety, and scalable production continue to impede broad clinical translation. This study offers a cutting-edge overview of graphene oxide-based biomedical systems and outlines promising pathways for advancing safer, more effective, and clinically relevant graphene-based healthcare technologies.

Due to rapid industrial growth, water pollution is worsening through the release of inorganic and organic pollutants, both soluble and insoluble, into water bodies. The rise of hazardous organic compounds and the high costs of various methods used to remediate industrial effluents containing dyes and metals are also of significant concern. Traditional wastewater treatment methods, including chemical precipitation, ion exchange, and membrane filtration, are often costly and can lead to secondary contamination. Biosorption is a novel, efficient, cost-effective, and sustainable method in which microbial biomass captures nonbiodegradable organic compounds from wastewater. This review illustrates the range of biosorbents, including fungi, yeasts, bacteria, agricultural residue, biopolymers, and plant-based materials, and their capacities in pollutant absorption. It clarifies the mechanisms of biosorption in detail and discusses the problems and opportunities aimed at advancing biosorbent efficiency in environmental remediation. Recent advancements in biosorption have led to the development of economical biomass-derived sorbents, functionalized biosorbents, and hybrid biological-nanomaterial systems to improve pollutant removal efficiency and reusability.

The rapid growth of wireless communication technologies has increased the need for effective microwave shielding to ensure device reliability and reduce electromagnetic pollution. Polymer composites have become viable alternatives to traditional metal-based electromagnetic interference (EMI) shielding due to their lightweight, corrosion-resistant, and tunable electrical, magnetic, and mechanical properties. However, conventional highly conductive shields, which primarily reflect incident waves, can lead to secondary electromagnetic interference. The challenge is to develop absorption-dominant, “green” EMI shields, which requires careful material selection and innovative structural design. This review provides an in-depth analysis of recent developments in EMI shielding materials, focusing on carbon-based nanomaterials, metals and alloys, MXenes, and polymer-based composites. It explores the underlying shielding mechanisms, including dielectric loss, magnetic loss, and internal multi-reflections, along with structural features and processing strategies. Emphasis is placed on techniques to maximize absorption and minimize reflection, such as gradient conductivity, porous structures, and multilayered interfaces. Finally, the review discusses future challenges and highlights the need for scalable fabrication of impedance-matched, absorption-dominant structures to meet the demands of future electronic and aerospace applications.

Surface-enhanced Raman spectroscopy (SERS) has emerged as a transformative tool in biomedical diagnostics, offering a highly sensitive and non-invasive method for detecting molecular biomarkers at exceptionally low concentrations. This approach takes advantage of the plasmonic characteristics of customized metallic nanostructures that produce intense localized electromagnetic fields via localized surface plasmon resonance and facilitate electron transfer reactions that notoriously enhance the intrinsically weak Raman scattering signals of molecular entities which reside on or next to their surfaces. SERS-based assays have shown remarkable potential in detecting cancer biomarkers, circulating tumor DNA (ctDNA), and proteins at early stages, enabling timely and targeted intervention. Additionally, the combination of SERS with AI-driven data analysis has facilitated real-time diagnostics, enhancing the precision and efficiency of point-of-care testing. Despite its promising capabilities, challenges such as substrate fouling, signal degradation, and the need for better biocompatibility remain. Nevertheless, ongoing research in substrate development, coupled with advances in AI, positions SERS as a leading technology for future diagnostic tools. This paper explores the current state of SERS in biomedical applications, highlighting its potential to revolutionize diagnostics and personalized medicine while addressing the existing limitations and future research directions.

Sustainable energy conversion cannot be achieved without the use of effective electrocatalysts for total water splitting. By combining CuCe ₂ Te ₄ with conductive polypyrrole (PPy), a CuCe ₂ Te ₄ @PPy nanocomposite was created using a hydrothermal technique in this study. We successfully formed crystalline orthorhombic CuCe ₂ Te ₄ @PPy with increased surface characteristics, as validated by structural and surface characterizations using XRD, SEM, FTIR, XPS, and BET studies. Excellent bifunctional catalytic activity was shown by electrochemical tests in an alkaline medium. At 10 mA cm ⁻² , the overpotentials for HER were 243 mV and for OER they were 181 mV, with modest Tafel slopes of 52.56 mV and 49.11 mV dec ⁻¹ , respectively. In addition, the catalyst showcased an impressive electrochemically active surface area (ECSA) of 510.25 cm ² and shown exceptional durability even after 50 h of continuous operation. Based on these findings, CuCe ₂ Te ₄ @PPy is an attractive and long‐lasting electrocatalyst that might be used for effective water splitting.

1. Solar cells have gained popularity over recent years because they are a pollution-free renewable source of energy and have enough energetic vitality to meet all the energy requirements of the wo...

Designing efficient, affordable, and durable electrocatalysts to drive water splitting is crucial for addressing the energy crisis and environmental issues. Transition metal-based materials are widely used for hydrogen and oxygen evolution reactions due to their tunable activity and abundance. However, challenges like low conductivity, agglomeration, and poor stability persist. Transition metal compounds have the potential to provide a solution by integrating carbon materials. This review examines the integration of transition metal compounds (TMCs) with carbon nanofibers (CNFs) and carbon nanotubes (CNTs) to enhance the efficiency of electrochemical water splitting, a vital process for sustainable hydrogen production. The mechanisms of hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) are discussed, emphasizing the role of electrocatalysts in mitigating overpotentials associated with these reactions. TMCs, when combined with CNFs and CNTs, create synergistic effects that improve reaction kinetics and increase active sites for catalysis. This review highlights recent advancements in the development of hybrid nanocomposites, detailing how their unique physicochemical properties facilitate effective electron transfer and enhance electrocatalytic activity and the stability of these integrated materials under harsh electrochemical conditions. Through a comprehensive examination of recent studies, this review aims to provide insights into the design and optimization of advanced electrocatalysts for efficient water splitting.