Promoted Hydrogen Peroxide Production from Pure Water on g-CN with Nitrogen Defects Constructed through Solvent-Precursor Interactions: Exploring a Complex Story in Piezo-Photocatalysis.

Hydrogen peroxide (HO) production via oxygen (O) reduction reaction (ORR) in pure water (HO) through graphitic carbon nitrides (g-CN)-based piezo-photocatalysts is an exciting approach in many current studies. However, the low Lewis-acid properties of g-CN limited the catalytic performance because of the low O adsorption efficacy. To overcome this challenge, the interaction of g-CN precursors with various solvents are utilized to synthesize g-CN, possessing multiple nitrogen-vacant species via thermal shocking polymerization.

Simultaneously Utilizing Excited Holes and Electrons for Piezoelectric-Enhanced Photoproduction of HO from S-Scheme 2D S-Doped VO/g-CN Nanostructures.

2D/2D step-scheme (S-scheme) piezo-photocatalysts for the production of fine chemicals, such as hydrogen peroxide (HO), have attracted significant attention of global scientists owing to the efficiency in utilizing surface piezoelectric effects from 2D materials to overcome rapid charge recombination in photocatalytic processes. In this research, we reported the fabrication of 2D S-doped VO deposited on 2D g-CN to produce HO via the piezo-photocatalytic process with high production yields at 20.19 mmol g h, which was 1.

Exploring the Effects of Various Two-Dimensional Supporting Materials on the Water Electrolysis of Co-Mo Sulfide/Oxide Heterostructure.

In this study, various two-dimensional (2D) materials were used as supporting materials for the bimetallic Co and Mo sulfide/oxide (CMSO) heterostructure. The water electrolysis activity of CMSO supported on reduced graphene oxide (rGO), graphite carbon nitride (gCN), and siloxene (SiSh) was better than that of pristine CMSO. In particular, rGO-supported CMSO (CMSO@rGO) exhibited a large surface area and a low interface charge-transfer resistance, leading to a low overpotential and a Tafel slope of 259 mV (10 mA/cm) and 85 mV/dec, respectively, with excellent long-term stability over 40 h of continuous operation in the oxygen evolution reaction.

Nano-Dimensional Carbon Nanosphere Supported Non-Precious Metal Oxide Composite: A Cathode Material for Sea Water Reduction.

Generation of hydrogen fuel at cathode during the electrolysis of seawater can be economically beneficial considering the vast availability of the electrolyte although it faces sluggishness caused by the anode reactions. In this regard a carbon nanosphere-protected CuO/CoO (CCuU) composite was synthesized through heat treatment and was used as the cathode material for electrocatalytic seawater splitting. CCuU showed a significantly low overpotential of 73 mV@10 mA cm, Tafel slope of 58 mV dec and relatively constant activity and morphology over a long time electrocatalytic study.

ZnO/Boron Nitride Quantum Dots Nanocomposites for the Enhanced Photocatalytic Degradation of Methylene Blue and Methyl Orange.

In this study, a heterostructure photocatalyst of ZnO nanoparticles decorated with boron nitride quantum dots (ZnO/BNQDs) was successfully synthesized by a simple solution procedure. The synthesized ZnO/BNQDs show that the BNQDs effectively suppress the recombination of photoinduced electrons and holes and the transfer of holes from ZnO nanoparticles by the formation of a heterojunction. The ZnO/BNQD nanocomposites thus demonstrate superior photocatalytic performances and excellent stability for the degradation of methylene blue (MB) and methyl orange (MO) under UV light irradiation.

Enhanced Electromagnetic Interference Shielding Properties of Immiscible Polyblends with Selective Localization of Reduced Graphene Oxide Networks.

Herein, an effective technique of curing reaction-induced phase separation (CRIPS) was used to construct a reduced graphene oxide (RGO) network in the immiscible diglycidyl ether of the bisphenol A/polyetherimide (DGEBA/PEI) polyblend system. The unique chemical reduction of RGO facilitated the reduction of oxygenated groups and simultaneously appended amino groups that stimulate the curing process. The selective interfacial localization of RGO was predicted numerically by the harmonic and geometric mean technique and further confirmed by field emission transmission electron microscopy (FETEM) analysis.

Designing an intriguingly fluorescent N, B-doped carbon dots based fluorescent probe for selective detection of NO ions.

Low-cost nitrogen and boron-doped carbon nanodots (CPAP-CDs) with a high quantum yield (64.07%) were synthesized through a facile hydrothermal treatment. The obtained CPAP-CDs exhibited wide absorption, strong fluorescence, and pH-dependent behavior.

Simple paper-based colorimetric and fluorescent glucose sensor using N-doped carbon dots and metal oxide hybrid structures.

A new strategy for the fluorescent and colorimetric sensing of hydrogen peroxide (HO) and glucose based on the metal oxide - carbon-dot hybrid structure was investigated. The sensing system is related to the catalytic oxidation reaction of glucose-by-glucose oxidase (GOx) to HO. In this study, a metal oxide hybrid with nitrogen-doped carbon dots (MFNCDs) that showed intrinsic peroxidase-like activity was synthesized and used as a catalyst instead of GOx to oxidize 3,3',5,5'-tetramethylbenzidine (TMB) to blue-emitting oxidized TMB (oxTMB) in the presence of hydrogen peroxide (HO).

Construction and Mechanism Analysis of a Self-Assembled Conductive Network in DGEBA/PEI/HRGO Nanocomposites by Controlling Filler Selective Localization.

Herein, a feasible and effective approach is developed to build an electrically conductive and double percolation network-like structure via the incorporation of highly reduced graphene oxide (HRGO) into a polymer blend of diglycidyl ether of bisphenol A/polyetherimide (DGEBA/PEI). With the assistance of the curing reaction-induced phase separation (CRIPS) technique, an interconnected network of HRGO is formed in the phase-separated structure of the DGEBA/PEI polymer blend due to selective localization behavior. In this study, HRGO was prepared from a unique chemical reduction technique.

Multicolor Emitting N-Doped Carbon Dots Derived from Ascorbic Acid and Phenylenediamine Precursors.

In this research, we report the green, blue, and orange color emitting N-doped carbon dots (CDs), which are being synthesized from ascorbic acid and o-/m-/p-phenylenediamine (o-PDA, m-PDA, and p-PDA, respectively). The effects of the solvent polarity and solution pH on the PL emission properties of the as-synthesized CDs have been systematically investigated. It has been observed that the PL emission of the as-synthesized CDs decreases with the increase in solvent polarity due to the greater agglomeration.

Uncovering the actual inner-filter effect between highly efficient carbon dots and nitroaromatics.

High performance sensors can be produced by adequately designing the chemical structure and uncovering the actual detection mechanism. In this study, a fluorescent probe was synthesized for various nitroaromatic molecules, including stereochemically varied nitrophenols and nitroaniline. A systematic investigation of the influence of various analytes on the luminescence behavior of the as-synthesized carbon dot (CDs) revealed the inner-filter effect to be the major detection mechanism.

ZnO-Associated Carbon Dot-Based Fluorescent Assay for Sensitive and Selective Dopamine Detection.

This paper presents a simple and highly efficient method for dopamine detection using water-soluble carbon dot nanoparticles. The ZnO-associated carbon dots (CDZs) were synthesized using a green chemical strategy. An examination of the effects of biomolecules on the fluorescence of CDZs revealed selective dopamine-induced quenching.

Effect of GO Additive in ZnO/rGO Nanocomposites with Enhanced Photosensitivity and Photocatalytic Activity.

Zinc oxide/reduced graphene oxide nanocomposites (ZnO/rGO) are synthesized via a simple one-pot solvothermal technique. The nanoparticle-nanorod turnability was achieved with the increase in GO additive, which was necessary to control the defect formation. The optimal defect in ZnO/rGO not only increased ZnO/rGO surface and carrier concentration, but also provided the alternative carrier pathway assisted with rGO sheet for electron-hole separation and prolonging carrier recombination.

Blue emitting nitrogen-doped carbon dots as a fluorescent probe for nitrite ion sensing and cell-imaging.

This study examined the efficiency of pH-dependent, fluorescent carbon dots for the sensing of hazardous anions in aqueous media and cell imaging. The nitrite anion, an important water-soluble element for environmental and biological systems, requires continuous monitoring because a high concentration can affect the systems severely. The as-synthesized carbon dots efficiently detected the nitrite anion in aqueous solution through a fluorescent 'Turn Off' phenomenon.

Reshaping of triangular silver nanoplates by a non-halide etchant and its application in melamine sensing.

Although triangular silver (Ag) nanoplates are intrinsically unstable, this characteristic has been taken advantage of in the development of a novel sensing platform. However, most of these applications have relied on halide ions as etchants. In the current work, we used sodium 4-vinylbenzenesulfonate (Na-VBS) as a new powerful etchant of triangular silver (Ag) nanoplates.

NiMnO spinel binary nanostructure decorated on three-dimensional reduced graphene oxide hydrogel for bifunctional materials in non-enzymatic glucose sensor.

Nickel-manganese spinel oxide (NiMnO) was hybridized with reduced graphene oxide hydrogel (rGOH) via a facile solvothermal process and a highly porous three-dimensional (3D) structure was constructed. NiMnO/rGOH exhibited excellent electrochemical performance due to the high specific surface area, excellent electrocatalytic activity, and enhanced electrical conductivity due to the synergetic effects between the two components. The NiMnO/rGOH exhibited excellent glucose sensing performance with high sensitivity (1310.

Three-Dimensional Porous Nitrogen-Doped NiO Nanostructures as Highly Sensitive NO₂ Sensors.

Nickel oxide has been widely used in chemical sensing applications, because it has an excellent p-type semiconducting property with high chemical stability. Here, we present a novel technique of fabricating three-dimensional porous nitrogen-doped nickel oxide nanosheets as a highly sensitive NO₂ sensor. The elaborate nanostructure was prepared by a simple and effective hydrothermal synthesis method.

Highly enhanced visible light water splitting of CdS by green to blue upconversion.

This paper reports a new class of visible light water splitting photocatalysts based on a triplet-triplet annihilation (TTA) upconversion (UC) process. The TTA-UC core composed of platinum-octaethyl-porphyrin (Pt(OEP)) and 9,10-diphenylanthracene (DPA) can upconvert low energy green light to high energy blue light with a high quantum yield. Using a silica nanocapsule (SNC), the quenching caused by oxygen can be avoided, even in aqueous solutions.

Non-Enzymatic Glucose Sensor Based on 3D Graphene Oxide Hydrogel Crosslinked by Various Diamines.

The non-enzymatic glucose sensor was fabricated by well-controlled and chemically crosslinked graphene oxide hydrogels (GOHs). By using various diamines such as ethylenediamine (EDA), p-phenylene diamine (pPDA) and o-phenylene diamine (oPDA) that have different amine to amine distance, we can control the structures of GOHs such as surface area and pore volume. The pPDA-GOH fabricated by pPDA exhibited the largest surface area and pore volume due to its longest amine to amine distance, which resulted in highest sensitivity in glucose and other monosaccharide sensing such as fructose (C6H12O6), galactose (C6H12O6) and sucrose (C12H22O11).

Durability Improvement of Pt/RGO Catalysts for PEMFC by Low-Temperature Self-Catalyzed Reduction.

Pt/C catalyst used for polymer electrolyte membrane fuel cells (PEMFCs) displays excellent initial performance, but it does not last long because of the lack of durability. In this study, a Pt/reduced graphene oxide (RGO) catalyst was synthesized by the polyol method using ethylene glycol (EG) as the reducing agent, and then low-temperature hydrogen bubbling (LTHB) treatment was introduced to enhance the durability of the Pt/RGO catalyst. The cyclic voltammetry (CV), oxygen reduction reaction (ORR) analysis, and transmittance electron microscopy (TEM) results suggested that the loss of the oxygen functional groups, because of the hydrogen spillover and self-catalyzed dehydration reaction during LTHB, reduced the carbon corrosion and Pt agglomeration and thus enhanced the durability of the electrocatalyst.

Surfactant-treated graphene covered polyaniline nanowires for supercapacitor electrode.

Surfactant-treated graphene/polyaniline (G/PANI) nanocomposites were prepared by the MnO2 template-aided oxidative polymerization of aniline (ANI) on the surfactant-treated graphene sheets. The electrochemical performances of the G/PANI nanocomposites in a three-electrode system using an aqueous sulfuric acid as an electrolyte exhibited a specific capacitance of 436 F g(-1) at 1 A g(-1), which is much higher than the specific capacitance of pure PANI (367 F g(-1)). Such a higher specific capacitance of the G/PANI nanocomposite inferred an excellent synergistic effect of respective pseudocapacitance and electrical double-layer capacitance of PANI and graphene.

Direct printing of reduced graphene oxide on planar or highly curved surfaces with high resolutions using electrohydrodynamics.

Electrohydrodynamic inkjet printing of reduced graphene oxide (RGO) is de-monstrated to form complex geometric devices with high resolution (line width ≈ 5 mm). Both planar and highly curved surfaces (radius of curvature ≈ 60 mm) can be used as substrates. Demonstrations of counterfeit coin recognition using RGO patterns and all-printed RGO transistors suggest substantial promise for applications in security and electronics.

Fabrication of 3D structured ZnO nanorod/reduced graphene oxide hydrogels and their use for photo-enhanced organic dye removal.

Hybrid 3-dimensional (3D) structures composed of zinc oxide (ZnO) nanorods and reduced graphene oxide hydrogel (rGOH) were fabricated by chemical reaction between Zn ions and GO followed by in-situ lateral growth of ZnO nanorods using Zn ions as seed points. The 3D networked ZnO nanorod-rGOH (ZNR-rGOH) fabricated in this study exhibited excellent methylene blue (MB) removal efficiency due to efficient physical adsorption of dye molecules because of electrostatic attractive forces and enhanced photocatalytic activity by the laterally grown ZnO nanorods. The Langmuir-Hinshelwood rate constant of ZNR-rGOH was 4-fold higher than that of pristine rGO due to the enhanced photocatalytic effects obtained by incorporating laterally grown ZnO nanorods inside the rGOH network.

Polymorphic transformations and optical properties of graphene-based Ag-doped titania nanostructures.

TiO2 is the most studied semiconductor material for photovoltaics and photocatalyst applications, but due to a very large electron hole recombination process it is difficult to use it as a photovoltaics material. In this context graphene-decorated Ag-doped TiO2 nanostructures have been synthesized by a simple, cost effective chemical method. In this paper, we have studied the structural transformations and electronic band structure of Ag-doped TiO2 due to the incorporation of graphene oxide.