Development of a ReaxFF Reactive Force Field for Pt/Cl Systems with Application to Platinum Metal Etching with Chlorine and Hydrogen Chloride Gases

In this study, we present the development of a ReaxFF Pt/Cl/H reactive force field designed to elucidate the etching process by Cl for Pt surfaces. The ReaxFF force field parameters were optimized based on a quantum mechanical training set, which included adsorption energies of Cl and dissociation of HCl on Pt(100) and Pt(111) surfaces, energy/volume relations of PtCl2 crystals, and Cl diffusion on Pt(100) and Pt(111) surfaces. The predictive capability of the force field was further established through molecular dynamics simulations, which investigated the interactions of Cl2 and HCl molecules with the (100) and (111) surfaces of c-Pt crystalline solid slabs. A comparative analysis revealed that the Pt (100) surface exhibited higher susceptibility to chlorination and etching, leading to a more dominant removal of surface Pt atoms, whereas the Pt (111) surface showed greater resistance to these processes. This resistance impeded the access of Cl atoms to the Pt surface, resulting in a slower formation of PtxCly molecules. The etching ratios between HCl and Cl2 were compared with experimental results, yielding satisfactory agreement. This indicates that the developed ReaxFF protocol serves as a valuable tool for studying atomistic-scale details of the etching process in platinum metal systems.

Redox double-switch cancer theranostics through Pt(IV) functionalised manganese dioxide nanostructures

Manganese dioxide (MnO₂)-based nanostructures have emerged as promising tumour microenvironment (TME) responsive platforms. Herein, we used a one-pot reaction to prepare MnO₂ nanostructures with Pt(IV) prodrugs as redox- (and thus TME-) responsive theranostics for cancer therapy, in which the Pt(IV) complexes act as prodrugs of cisplatin (Pt(II)), a clinical chemotherapeutic drug. The cytotoxicity of these MnO₂-Pt(IV) probes was evaluated in two and three dimensional (2D and 3D) A549 cell models and found to be as effective as active drug cisplatin in 3D models. Moreover, MnO₂-Pt(IV) nanoparticles exhibited strong off/ON magnetic resonance (MR) contrast in response to reducing agents, with the longitudinal relaxivity (r₁) increasing 136-fold upon treatment with ascorbic acid. This off/ON MR switch was also observed in (2D and 3D) cells in vitro. In vivo MRI experiments revealed that the nanostructures induce a strong and long-lasting T₁ signal enhancement upon intratumoral injection in A549 tumour-bearing mice. These results show the potential of MnO₂-Pt(IV) NPs as redox responsive MR theranostics for cancer therapy.

Synthesis of Platinum Nanocrystals Dispersed on Nitrogen-Doped Hierarchically Porous Carbon with Enhanced Oxygen Reduction Reaction Activity and Durability

Platinum-based catalysts are widely used for efficient catalysis of the acidic oxygen reduction reaction (ORR). However, the agglomeration and leaching of metallic Pt nanoparticles limit the catalytic activity and durability of the catalysts and restrict their large-scale commercialization. Therefore, this study aimed to achieve a uniform distribution and strong anchoring of Pt nanoparticles on a carbon support and improve the ORR activity and durability of proton-exchange membrane fuel cells. Herein, we report on the facile one-pot synthesis of a novel ORR catalyst using metal-nitrogen-carbon (M-N-C) bonding, which is formed in situ during the ion exchange and pyrolysis processes. An ion-exchange resin was used as the carbon source containing R-N+(CH3)3 groups, which coordinate with PtCl62- to form nanosized Pt clusters confined within the macroporous framework. After pyrolysis, strong M-N-C bonds were formed, thereby preventing the leaching and aggregation of Pt nanoparticles. The as-synthesized Pt supported on the N-doped hierarchically porous carbon catalyst (Pt/NHPC-800) showed high specific activity (0.3 mA cm-2) and mass activity (0.165 A mgPt-1), which are approximately 2.7 and 1.5 times higher than those of commercial Pt/C, respectively. The electrochemical surface area of Pt/NHPC-800 remained unchanged (~1% loss) after an accelerated durability test of 10,000 cycles. The mass activity loss after ADT of Pt/NHPC-800 was 18%, which is considerably lower than that of commercial Pt/C (43%). Thus, a novel ORR catalyst with highly accessible and homogeneously dispersed Pt-N-C sites, high activity, and durability was successfully prepared via one-pot synthesis. This facile and scalable synthesis strategy for high-efficiency catalysts guides the further synthesis of commercially available ORR catalysts.

Platinum-based drug-induced depletion of amino acids in the kidneys and liver

Cisplatin (cis-diamminedichloroplatinum II; CDDP) is a widely used cytostatic agent; however, it tends to promote kidney and liver disease, which are a major signs of drug-induced toxicity. Platinum compounds are often presented as alternative therapeutics and subsequently easily dispersed in the environment as contaminants. Due to the major roles of the liver and kidneys in removing toxic materials from the human body, we performed a comparative study of the amino acid profiles in chicken liver and kidneys before and after the application of CDDP and platinum nanoparticles (PtNPs-10 and PtNPs-40). The treatment of the liver with the selected drugs affected different amino acids; however, Leu and Arg were decreased after all treatments. The treatment of the kidneys with CDDP mostly affected Val; PtNPs-10 decreased Val, Ile and Thr; and PtNPs-40 affected only Pro. In addition, we tested the same drugs on two healthy cell lines, HaCaT and HEK-293, and ultimately explored the amino acid profiles in relation to the tricarboxylic acid cycle (TCA) and methionine cycle, which revealed that in both cell lines, there was a general increase in amino acid concentrations associated with changes in the concentrations of the metabolites of these cycles.

Development of an electrochemical enzyme-free glucose sensor based on self-assembled Pt-Pd bimetallic nanosuperlattices

The huge demand for the clinical diagnosis of diabetes mellitus has prompted the development of great-performance sensing platforms for glucose detection. Non-enzymatic glucose sensors are getting closer to their use in realistic applications. In this work, polyvinylpyrrolidone (PVP)-conjugated bimetallic Pt-Pd nanosuperlattices were synthesized precisely through a simple synthesis procedure, leading to controllable spherical morphologies with significantly fine and precise nanostructures in a size range of ∼3-5 nm by the reduction of Pt and Pd precursors in ethylene glycol, using an ultrasonic method. High-resolution transmission electron microscopy (HRTEM) measurements evidenced the formation of Pt-Pd bimetallic nanosuperlattices (BMNSLs). The superlattice-fringe patterns (111) of bimetallic Pt-Pd NSLs were identified in the HRTEM images, clearly showing their crystalline nature. The prepared material was used in the electrochemical oxidation of glucose using voltammetry analyses. The experimental evidence indicates that the Pt-Pd BMNSL modified glassy carbon electrode is effective for the selective amperometric detection of glucose in the presence of galactose, sucrose, fructose, lactose, and ascorbic acid. Moreover, its application in the detection of glucose in real serum and urine samples was assessed and good recoveries are achieved. The results show that a Pt-Pd bimetallic nanosuperlattice with high surface area, catalytic activity, and superior selectivity could be a promising material in the generation of novel electrodes for low-cost non-enzymatic glucose sensors.

Carbon-Based Nanocages: A New Platform for Advanced Energy Storage and Conversion

Energy storage and conversion play a crucial role in modern energy systems, and the exploration of advanced electrode materials is vital but challenging. Carbon-based nanocages consisting of sp² carbon shells feature a hollow interior cavity with sub-nanometer microchannels across the shells, high specific surface area with a defective outer surface, and tunable electronic structure, much different from the intensively studied nanocarbons such as carbon nanotubes and graphene. These structural and morphological characteristics make carbon-based nanocages a new platform for advanced energy storage and conversion. Up-to-date synthetic strategies of carbon-based nanocages, the utilization of their unique porous structure and morphology for the construction of composites with foreign active species, and their significant applications to the advanced energy storage and conversion are reviewed. Structure-performance correlations are discussed in depth to highlight the contribution of carbon-based nanocages. The research challenges and trends are also envisaged for deepening and extending the study and application of this multifunctional material.

Development of Porous Pt Electrocatalysts for Oxygen Reduction and Evolution Reactions

Porous Pt electrocatalysts have been developed as an example of carbon-free porous metal catalysts in anticipation of polymer electrolyte membrane (PEM) fuel cells and PEM water electrolyzers through the assembly of the metal precursor and surfactant. In this study, porous Pt was structurally evaluated and found to have a porous structure composed of connected Pt particles. The resulting specific electrochemical surface area (ECSA) of porous Pt was 12.4 m² g⁻¹, which was higher than that of commercially available Pt black. Accordingly, porous Pt showed higher oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) activity than Pt black. When the activity was compared to that of a common carbon-supported electrocatalyst, Pt/ketjen black (KB), porous Pt showed a comparable ORR current density (2.5 mA cm⁻² at 0.9 V for Pt/KB and 2.1 mA cm⁻² at 0.9 V for porous Pt), and OER current density (6.8 mA cm⁻² at 1.8 V for Pt/KB and 7.0 mA cm⁻¹ at 1.8 V), even though the ECSA of porous Pt was only one-sixth that of Pt/KB. Moreover, it exhibited a higher durability against 1.8 V. In addition, when catalyst layers were spray-printed on the Nafion^® membrane, porous Pt displayed more uniform layers in comparison to Pt black, showing an advantage in its usage as a thin layer.

Monodisperse Pt-Co/GO anodes with varying Pt: Co ratios as highly active and stable electrocatalysts for methanol electrooxidation reaction

The intense demand for alternative energy has led to efforts to find highly efficient and stable electrocatalysts for the methanol oxidation reaction. For this purpose, herein, graphene oxide-based platinum-cobalt nanoparticles (Pt100-xCox@GO NPs) were synthesized in different ratios and the synthesized nanoparticles were used directly as an efficient electrocatalyst for methanol oxidation reaction (MOR). The characterizations for the determination of particle size and surface composition of nanoparticles were performed by transmission electron microscopy (TEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The structure of the catalysts was detected as face-centered cubic and the dispersion of them on graphene oxide was homogenous (distributed narrowly (4.01 ± 0.51 nm)). Cyclic voltammetry (CV) and chronoamperometry (CA) was utilized for testing electrocatalytic activities of all prepared NPs for the methanol oxidation reaction. It was detected that the newly produced NPs were more active and stable than commercially existing Pt(0)/Co nanomaterial in methanol electro-oxidation in acidic media.

In vitro evaluation of Pt-coated electrospun nanofibers for endovascular coil embolization

Recently, endovascular coil embolization has been introduced to treat intracranial aneurysms because it has lower morbidity and mortality than surgical clipping. The endovascular coils prevent the extravasation of blood by decreasing the permeability of an aneurysm flow governed by Darcy's law. Here, we developed and explored Pt-coated micro-ropes for potential use as endovascular coils. Electrospinning with subsequent electroplating were employed to fabricate Pt-coated nanofibers, which were tightly twisted to form micro-ropes. The compatibility of Pt micro-ropes with commercial delivery catheters was verified and their performance was experimentally explored in an in vitro experimental model. The developed Pt-coated micro-ropes demonstrated feasibility as efficient and low-cost endovascular coils. STATEMENT OF SIGNIFICANCE: The use of Platinum (Pt)-coated polymer nanofibers to prevent blood extravasation has been demonstrated. These Pt nanofibers were installed within a microfluidic channel, and the resulting reduced permeability was evaluated using a fluid similar to blood. Based on the obtained results, these newly developed nanofibers are expected to decrease the operation cost for aneurysmal subarachnoid hemorrhage (SAH), owing their reduced size and low material cost. Overall, the use of this new material should reduce the operational risk associated with the multiple steps required to place the Pt coils at the SAH site. The compatibility of Pt micro-ropes with commercial delivery catheters was verified and their performance was experimentally explored in an in vitro experimental model. The developed Pt-coated micro-ropes demonstrated feasibility as efficient and low-cost endovascular coils.

Rapid synthesis of ultrasmall platinum nanoparticles supported on macroporous cellulose fibers for catalysis

Herein, we report a facile method for the synthesis of platinum nanoparticles (PtNPs) about 2.25 nm in size by heating a solution of chloroplatinic acid and sodium rhodizonate. The PtNPs were synthesized in about 5 min. The PtNPs were supported on macroporous cellulose fibers that were obtained from Kimwipe paper (KWP). The cellulose fiber-supported PtNPs (PtNPs@KWP) exhibited excellent catalytic activity towards the reduction of organic pollutants [e.g. methyl orange (MO)] in the presence of hydrogen (H₂) gas and formic acid (FA). FA and H₂ gas were utilized as clean and alternative reducing agents. The reduction of MO was performed in two different types of water matrices viz. deionized water (DIW) and simulated fresh drinking water (FDW). In both water matrices, the FA mediated reduction of MO was found to be faster than the H₂ gas-bubbled one. The PtNPs@KWP demonstrated excellent cycling stability without leaching the PtNPs or platinum ions into the solution for at least five cycles.

Stabilizing the active phase of iron-based Fischer-Tropsch catalysts for lower olefins: mechanism and strategy

An iron carbonyl-mediated Ostwald-ripening-like growth mechanism of an Fe_xC_y active phase in Fischer–Tropsch synthesis is firstly revealed by in situ mass-spectrometric and theoretical analysis.

Fischer–Tropsch synthesis of lower olefins (FTO) is a classical yet modern topic of great significance in which the supported Fe-based nanoparticles are the most promising catalysts. The performance deterioration of catalysts is a big challenge due to the instability of the nanosized active phase of iron carbides. Herein, by in situ mass spectrometry, theoretical analysis, and atmospheric- and high-pressure experimental examinations, we revealed the Ostwald-ripening-like growth mechanism of the active phase of iron carbides in FTO, which involves the cyclic formation–decomposition of iron carbonyl intermediates to transport iron species from small particles to large ones. Accordingly, by suppressing the formation of iron carbonyl species with a high-N-content carbon support, the size and structure of the active phase were regulated and stabilized, and durable iron-based catalysts were conveniently obtained with the highest selectivity for lower olefins up to 54.1%. This study provides a practical strategy for exploring advanced FTO catalysts.

Boosting oxygen reduction activity of spinel CoFe2O4 by strong interaction with hierarchical nitrogen-doped carbon nanocages

The unique hierarchical nitrogen-doped carbon nanocages (hNCNC) are used as a new support to homogeneously immobilize spinel CoFe₂O₄ nanoparticles by a facile solvothermal method. The so-constructed hierarchical CoFe₂O₄/hNCNC catalyst exhibits a high oxygen reduction activity with an onset potential of 0.966V and half-wave potential of 0.819V versus reversible hydrogen electrode, far superior to the corresponding 0.846 and 0.742V for its counterpart of CoFe₂O₄/hCNC with undoped hierarchical carbon nanocages (hCNC) as the support, which locates at the top level for spinel-based catalysts to date. Consequently, the CoFe₂O₄/hNCNC displays the superior performance to the CoFe₂O₄/hCNC, when used as the cathode catalysts in the home-made Al-air batteries. X-ray photoelectron spectroscopy characterizations reveal the more charge transfer from CoFe₂O₄ to hNCNC than to hCNC, indicating the stronger interaction between CoFe₂O₄ and hNCNC due to the nitrogen participation. The enhanced interaction and hierarchical morphology favor the high dispersion and modification of electronic states for the active species as well as the mass transport during the oxygen reduction process, which plays a significant role in boosting the electrocatalytic performances. In addition, we noticed the high sensitivity of O 1s spectrum to the particle size and chemical environment for spinel oxides, which is used as an indicator to understand the evolution of ORR activities for all the CoFe₂O₄-related contrast catalysts. Accordingly, the well-defined structure-performance relationship is demonstrated by the combination of experimental characterizations with theoretical calculations. This study provides a promising strategy to develop efficient, inexpensive and durable oxygen reduction electrocatalysts by tuning the interaction between spinel metal oxides and the carbon-based supports.

From Carbon-Based Nanotubes to Nanocages for Advanced Energy Conversion and Storage

Carbon-based nanomaterials have been the focus of research interests in the past 30 years due to their abundant microstructures and morphologies, excellent properties, and wide potential applications, as landmarked by 0D fullerene, 1D nanotubes, and 2D graphene. With the availability of high specific surface area (SSA), well-balanced pore distribution, high conductivity, and tunable wettability, carbon-based nanomaterials are highly expected as advanced materials for energy conversion and storage to meet the increasing demands for clean and renewable energies. In this context, attention is usually attracted by the star material of graphene in recent years. In this Account, we overview our studies on carbon-based nanotubes to nanocages for energy conversion and storage, including their synthesis, performances, and related mechanisms. The two carbon nanostructures have the common features of interior cavity, high conductivity, and easy doping but much different SSAs and pore distributions, leading to different performances. We demonstrated a six-membered-ring-based growth mechanism of carbon nanotubes (CNTs) with benzene precursor based on the structural similarity of the benzene ring to the building unit of CNTs. By this mechanism, nitrogen-doped CNTs (NCNTs) with homogeneous N distribution and predominant pyridinic N were obtained with pyridine precursor, providing a new kind of support for convenient surface functionalization via N-participation. Accordingly, various transition-metal nanoparticles were directly immobilized onto NCNTs without premodification. The so-constructed catalysts featured high dispersion, narrow size distribution and tunable composition, which presented superior catalytic performances for energy conversions, for example, the oxygen reduction reaction (ORR) and methanol oxidation in fuel cells. With the advent of the new field of carbon-based metal-free electrocatalysts, we first extended ORR catalysts from the electron-rich N-doped to the electron-deficient B-doped sp² carbon. The combined experimental and theoretical study indicated the ORR activity originated from the activation of carbon π electrons by breaking the integrity of π conjugation, despite the electron-rich or electron-deficient nature of the dopants. With this understanding, metal-free electrocatalysts were further extended to the dopant-free defective carbon nanomaterials. Moreover, we developed novel 3D hierarchical carbon-based nanocages by the in situ MgO template method, which featured coexisting micro-meso-macropores and much larger SSA than the nanotubes. The unique 3D architecture avoids the restacking generally faced by 2D graphene due to the intrinsic π-π interaction. Consequently, the hierarchical nanocages presented superior performances not only as new catalyst supports and metal-free electrocatalysts but also as electrode materials for energy storage. State-of-the-art supercapacitive performances were achieved with high energy density and power density, as well as excellent rate capability and cycling stability. The large interior space of the nanocages enabled the encapsulation of high-loading sulfur to alleviate polysulfide dissolution while greatly enhancing the electron conduction and Li-ion diffusion, leading to top level performance of lithium-sulfur battery. These results not only provide unique carbon-based nanomaterials but also lead to in-depth understanding of growth mechanisms, material design, and structure-performance relationships, which is significant to promote their energy applications and also to enrich the exciting field of carbon-based nanomaterials.

Microbial synthesis of bimetallic PdPt nanoparticles for catalytic reduction of 4-nitrophenol

Bimetallic nanoparticles are generally believed to have improved catalytic activity and stability due to geometric and electronic changes. In this work, biogenic-Pd (bio-Pd), biogenic-Pt (bio-Pt), and biogenic-PdPt (bio-PdPt) nanoparticles were synthesized by Shewanella oneidensis MR-1 in the absence or presence of quinone. Compared with direct microbial reduction process, the addition of anthraquinone-2,6-disulfonate (AQDS) could promote the reduction efficiency of Pd(II) or/and Pt(IV) and result in decrease of particles size. All kinds of nanoparticles could catalyze 4-nitrophenol reduction by NaBH₄ and their catalytic activities took the following order: bio-PdPt (AQDS) ∼ bio-PdPt > bio-Pd (AQDS) > bio-Pd > bio-Pt (AQDS) ∼ bio-Pt. Moreover, the bio-PdPt (AQDS) nanoparticles could be reused for 6 cycles. We believe that this simple and efficient biosynthesis approach for synthesizing bimetallic bio-PdPt nanocatalysts is important for preparing active and stable catalysts.

Manganese oxide-induced strategy to high-performance iron/nitrogen/carbon electrocatalysts with highly exposed active sites

Iron/nitrogen/carbon (Fe/N/C) catalyst is so far the most promising non-precious metal electrocatalyst for oxygen reduction reaction (ORR) in acidic medium, whose performance depends closely on the synthesis chemistry. Herein, we report a MnOx-induced strategy to construct the Fe/N/C with highly exposed Fe-Nx active sites, which involves the uniform spreading of polyaniline on hierarchical N-doped carbon nanocages by a reactive-template polymerization, followed by the successive iron incorporation and polyaniline pyrolysis. The resulting Fe/N/C demonstrates an excellent ORR performance, including an onset potential of 0.92 V (vs. RHE), four electron selectivity, superb stability and immunity to methanol crossover. The excellent performance is well correlated with the greatly enhanced surface active sites of the catalyst stemming from the unique MnOx-induced strategy. This study provides an efficient approach for exploring the advanced ORR electrocatalysts by increasing the exposed active sites.

In situ synthesis of N-doped carbon nanotubes–BiOCl nanocomposites and their synergistic photocatalytic performance

N-Doped carbon nanotube–BiOCl (NCB) nanocomposites were prepared by an in situ growth strategy. The NCB nanocomposites possessed enhanced photocatalytic efficiency, compared with CN_xNTs, BiOCl 3D flower-like hierarchitectures, and P25.

A facile one-pot solvothermal synthesis of CoFe2O4/RGO and its excellent catalytic activity on thermal decomposition of ammonium perchlorate

A novel catalyst CoFe₂O₄/RGO has been synthesized and shows enhanced catalytic activity on thermal decomposition of ammonium perchlorate.

Functionalization effect on a Pt/carbon nanotube composite catalyst: a first-principles study

Chemical interactions between Pt and both pristine and defective carbon nanotubes (CNTs) that were functionalized with various surface functional groups, including atomic oxygen (–O), atomic nitrogen (–N), hydroxyl (–OH) and amine (–NH₂) groups, were investigated through first-principles calculations.

Enhancing the photovoltaic performance and stability of QDSSCs using surface reinforced Pt nanostructures with controllable morphology and superior electrocatalysis via cost-effective chemical bath deposition

Several metal sulfides Pt CEs were studied as CEs for QDSSCs.

Alternating Current Dielectrophoresis Optimization of Pt-Decorated Graphene Oxide Nanostructures for Proficient Hydrogen Gas Sensor

Alternating current dielectrophoresis (DEP) is an excellent technique to assemble nanoscale materials. For efficient DEP, the optimization of the key parameters like peak-to-peak voltage, applied frequency, and processing time is required for good device. In this work, we have assembled graphene oxide (GO) nanostructures mixed with platinum (Pt) nanoparticles between the micro gap electrodes for a proficient hydrogen gas sensors. The Pt-decorated GO nanostructures were well located between a pair of prepatterned Ti/Au electrodes by controlling the DEP technique with the optimized parameters and subsequently thermally reduced before sensing. The device fabricated using the DEP technique with the optimized parameters showed relatively high sensitivity (∼10%) to 200 ppm hydrogen gas at room temperature. The results indicates that the device could be used in several industry applications, such as gas storage and leak detection.

N-doped graphene as an electron donor of iron catalysts for CO hydrogenation to light olefins

N-doped graphene used as an efficient electron donor of iron catalysts for CO hydrogenation can achieve a high selectivity of around 50% for light olefins, significantly superior to the selectivity of iron catalysts on conventional carbon materials, e.g. carbon black with a selectivity of around 30% at the same reaction conditions.

The effect of Pt NPs crystallinity and distribution on the photocatalytic activity of Pt-g-C3N4

Loading of a co-catalyst on the surface of a semiconductor photocatalyst is often carried out without considering the effect of the loading procedure on the final product. The present study looks in detail at the effect that the loading method has on the morphology and final composition of platinum-based nanoparticles by means of XPS and TEM analysis. Additionally, reduction pre-treatments are performed to investigate how the coverage, crystallinity and composition of the NPs affect the photocatalytic H2 evolution. The activity of Pt-g-C3N4 can significantly be enhanced by controlling the properties of the co-catalyst NPs.

Nitrogen-doped carbon nanotubes and graphene composite structures for energy and catalytic applications

Substitutional heteroatom doping is a promising route to modulate the outstanding material properties of carbon nanotubes and graphene for customized applications. Recently, (nitrogen-) N-doping has been introduced to ensure tunable work-function, enhanced n-type carrier concentration, diminished surface energy, and manageable polarization. Along with the promising assessment of N-doping effects, research on the N-doped carbon based composite structures is emerging for the synergistic integration with various functional materials. This invited feature article reviews the current research progress, emerging trends, and opening opportunities in N-doped carbon based composite structures. Underlying basic principles are introduced for the effective modulation of material properties of graphitic carbons by N-doping. Composite structures of N-doped graphitic carbons with various functional materials, including (i) polymers, (ii) transition metals, (iii) metal oxides, nitrides, sulphides, and (iv) semiconducting quantum dots are highlighted. Practical benefits of the synergistic composite structures are investigated in energy and catalytic applications, such as organic photovoltaics, photo/electro-catalysts, lithium ion batteries and supercapacitors, with a particular emphasis on the optimized interfacial structures and properties.