The Front Cover picture shows the growth of strategic polyolefin catalyst research since 1990 in the Interdisciplinary Research Center for Refining & Advanced Chemicals (IRCRAC) at the Research Institute of King Fahd University of Petroleum & Minerals, Dhahran, Saudi Arabia. Our vision is to transform Saudi Arabia into an international hub and leader of polyolefin education, research, training, manufacturing, application, and business. See the Personal Account by M. Atiqullah and H. S. Al-Asiri (DOI:10.1002/tcr.202100321).

Saudi Arabia in recent years has made considerable progress in the field of chemistry and material science, especially in topics, such as nanotechnology, energy storage, and photovoltaics. This special issue comprises high-quality contributions by researchers in the country.

The Interdisciplinary Research Center for Refining & Advanced Chemicals (IRCRAC) at the Research Institute (RI) of King Fahd University of Petroleum & Minerals (KFUPM), Dhahran depicts its polyolefin (PO) catalyst research vision and path forward that match Saudi Arabia's Vision 2030. Polyolefins top the tertiary petrochemicals and make the country a global leader. Materialization and realization of this PO vision will immensely benefit Saudi Arabia in so many ways.

Hybrid supercapacitors (HSCs) are efficient electrochemical energy storage devices, typically developed with a high-rate capacitive electrode and high-capacity pseudocapacitor-type electrode and have attracted considerable research attention due to their potential applications in electric vehicles, smart electric grids, and even miniaturized electronic/optoelectronic devices. This review addresses the fundamental scientific principles, structures, and possible classifications of HSCs before reviewing recent advances on various carbonaceous and redox-active nanoarchitectures for HSCs.

Electrochemically deposited metals/metal composites are considered efficient electrode materials for supercapacitors. This review aims to illustrate the electrode materials loaded on various conductive substrates by electrochemical deposition employed for supercapacitors to provide broad knowledge on synthetic pathways, which will pave the way for future research. We also discussed the basic parameters involved in supercapacitor studies and the advantages of the electrochemical deposition techniques through literature analysis.

Supramolecules are complex chemical systems in which molecules interact through non-covalent bonding processes. Supramolecules are ideal candidates for use in supercapacitors due to their unique properties, such as the gel system possessing self-healing capabilities, high conductivity, and resistance to stress-induced deformation. This review discusses different types of supramolecules and the utilization of different supramolecular elements that enhance supercapacitor performance.

Several methods have been devoted to separating or removing heavy metals from wastewater. Among them, membrane distillation (MD) has become one of the most attractive approaches due to its higher rejection rate than processes driven by pressure and lower energy consumption than traditional distillation processes. MD has gained significant attention for removing heavy metals than other techniques like ion exchange and adsorption in the last two decades. This review provides insight knowledge to the reader and focuses on how heavy metals impact humans and the environment, sources of heavy metals, and their removal methods using the MD method.

Nanoparticles system (Figure a) and corresponding near-field TPI-PL (Figure b) acquired simultaneously along with schematic of plasmon excitation (Figure c) and simulative near-field distribution of an archetype dimer (Figure d).

A brief overview of recent advancements in the processing and applying heterobimetallic oxide thin films produced by aerosol-aided chemical vapor deposition (AACVD) is presented. As a variant of conventional CVD, AACVD provides a flexible and cost-effective deposition approach and an alternative to chemical precursor supply and delivery difficulties of the CVD process. This review paper summarizes the AACVD factors affecting the structural outcomes, processing concepts, applications, and research and development prospects in this field.

In this article we have summarized the recent developments on the MOF-derived electrocatalysts for the electrochemical ORR and CO₂RR. The MOF-derived porous carbons, metal/carbon and single-atom catalysts (SACs) are widely used as potential catalysts.

Magnetic metal oxide nanoparticles for imaging, therapy and theranosctics in breast cancer.

In the fields of soft bioelectronics, biosensing and therapeutics, great advances have been achieved by implementing nanocarbon materials either as a carrier or building blocks for device fabrications. This review summarizes the recent advancement of two mostly explored nanocarbons i.e., graphene and carbon nanotubes (CNTs) in these fields, realizing their mechanisms, functions in the device design and performance in the aforementioned areas. The review also highlights the challenges involved in these fields and look forward envisioning emerging prospects of nanocarbons in soft-bioelectronics and biosensing.

This review emphasized the composition and characteristics of recent development on g-C₃N₄ based materials. Various fabrication methodologies for g-C₃N₄ and g-C₃N₄-based materials were focused and evaluated in this report. Methods for enhancing the photocatalytic performance of g-C₃N₄ based materials. Most important aspects were extensively explored.

By considering the importance of single-atom catalysts (SACs), this article discussed the recent methods for the fabrication of SACs and their utilization for the energy devices such as metal-air batteries, metal-CO₂ batteries, and metal-sulfur batteries. The role of SACs is critically analyzed to solve the bottle-neck problems of these energy storage devices with future perspectives.

ZnO nanostructures and H₂ sensing responses (left panel), Pt−ZnO sensing constructs and H₂ sensing responses (middle panel) and Pt−rGO−ZnO sensing construct and H₂ sensing responses (right panel) along with a plausible mechanism.

A combination of graphene with inorganic NPs offers enhanced properties for different catalytic applications. This review showcase strategies to synthesize graphene/inorganic NPs nanocomposites on different scales. In addition, the factors contributing in increased efficiencies for their catalytic applcations are highlited.

This review presents various strategies used to enhance ZnO photocatalyst's performance for water treatment. It summarizes the efforts made to improve the photocatalytic activity of pristine ZnO through tuning its morphology, surface area, exposed face, and intrinsic defects. The review also explains the effect of doping, defects, and how the Z-scheme approach succeed to address the redox weakened issue of heterojunction approach.

In this account review, we have discussed the oil/water separation by using the membranes. Ceramic and polymeric membranes are summarized for their application to treat oily wastewater. The major challenges in membranes-based separation processes are also discussed.

Vegetative and food waste derived biodegradable packaging films from a sustainability perspective.

In this review, we presented global mercury emission, threat to ecosystem, methylation process, and analytical challenges for mercury sensing. It summarizes the recent progress in colorimetric-, electrochemical-, fluorescence-, and SERS-based sensors for mercury detection in aqueous environments. The performance of these sensors has been compared and future perspectives on the selective detection of organomercury species have been provided

Single atom catalysts (SACs) have the potential to revolutionize the field of heterogeneous catalysis. The use of a single atomic layer of the active catalyst phase brings a huge saving in catalyst cost. Additionally, activity and selectivity are significantly improved with down-sizing the catalytic particles to an atomic level. With a single atomic layer of the active catalytic phase, coordination of the single atoms and their interactions with supports can be tuned in a way to improve catalytic performance. Thus, coordination and support-SACs interactions are the focus of this review.

The capacitance of a perovskite solar cell varies with frequency, illumination intensity, device temperature, applied bias, as well as the perovskites/charge selective contact interface. The stable plateau at intermediate frequency is assigned to the geometrical capacitance of the perovskites layer, whereas a giant photoinduced capacitance at low frequency is ascribed to the charge accumulation at perovskites/selective contact interface. The accumulated interfacial charge delays the response to the external bias and amends the interfacial barrier height, consequently impacting the charge carrier kinetics in perovskites solar cells.

This review article summarizes the recent advancements made in visible-light-driven water splitting covering the aspects of synthetic strategies and experimental parameters employed for water splitting reactions with special emphasis on conjugated polymers such as linear CPs, planarized CPs, graphitic carbon nitride (g-C₃N₄), conjugated microporous polymers (CMPs), covalent organic frameworks (COFs), and conjugated polymer-based nanocomposites (CPNCs).

Reactor size, configuration and hydrodynamics greatly influence the oxygen availability and mixing within the reactor, and hence, influence the conversion and product selectivity during liquid phase oxidation of hydrocarbon.

Utilizing blue ammonia to generate carbon-neutral power has received global attention after Saudi Arabia's first shipment to Japan to boost hydrogen energy future prospects. Ammonia decomposition requires catalyst with high activity, stability, economic viability and potential for scale-up applications. Recent developments in bimetallic catalysts for ammonia decomposition have shown the metal-metal alloy can offer an efficient alternative to existing catalysts system.

The major aspects of CO₂ remediation (capture and conversion) by SAPO-34 zeolite materials have been reviewed.

The review provides the most recent updates on drug delivery by two important classes of ‘supramolecules & assemblies’, namely macrocycles and supramolecular gels.

The distinctive aim of this manuscript is to comprehensively review the development of optical chemical sensors for iodide ions sensing, their design and synthetic strategies to avoid limitations concerning its large size and high polarizability, and challenges in real samples as well as probable future aspects.

Formic acid fuel cell is unique because it can be coupled with electrochemical reduction of carbon dioxide to achieve a carbon neutral energy source. Formic acid oxidation takes place over the palladium based anode catalysts. In this review, the recent advances in palladium-based anode electrocatalysts for formic acid oxidation have been discussed.

The recent achievements of Ni−MOFs and their derivatives as catalysts, membrane materials for CO₂ separation and conversion, electrode materials and their respective performance have been discussed in this review.

In this review, an extensive literature survey has been covered to comprehensively summarize the strategies adopted in MOFs for CO₂ capture and separation.

The present review describes the recent progress in applications of starch-based composites for the adsorptive removal of dyes from water.