A novel approach to the quantitative analysis of the particulate matter in conventional cigarette smoke and heated tobacco product aerosols.

The particulate and soluble matter present in aerosols from combustible cigarettes (CCs) and Heated Tobacco Products (HTPs) was collected in liquid water. These liquids, yellowish in the experiments with cigarettes and colourless after using HTPs, were analysed by Laser Diffraction (LD) and by Transmission Electron Microscopy coupled to Energy Dispersive X-ray spectroscopy (TEM-EDX) to study the amount, size, composition, and other features of the particulate matter (PM) present in the collected aerosols. The particulate matter concentration in HTPs samples is below the limit of quantification for LD, and only samples from cigarettes show a particulate matter concentration above such limit.

Removal of malachite green from water: Comparison of adsorption in a residue-derived AC versus photocatalytic oxidation with TiO and study of the adsorption-photocatalysis synergy.

The literature rarely compiles studies devoted to the removal of pollutants in aqueous media comparing adsorption and photocatalytic degradation, and does not pay enough attention to the analysis of combined adsorption-photocatalytic oxidation processes. In the present manuscript, the removal of malachite green (MG) from aqueous solutions has been investigated in three different sustainable scenarios: i) adsorption on activated carbon (AC) derived from a residue, luffa cylindrica, ii) photocatalytic oxidation under simulated solar light using titanium dioxide (TP) and iii) combined adsorption-photocatalytic oxidation using TP-AC (70/30 wt./wt.

Impact of TiO Reduction and Cu Doping on Bacteria Inactivation under Artificial Solar Light Irradiation.

Preparation of TiO using the hydrothermal treatment in NHOH solution and subsequent thermal heating at 500-700 °C in Ar was performed in order to introduce some titania surface defects. The highest amount of oxygen vacancies and Ti surface defects were observed for a sample heat-treated at 500 °C. The presence of these surface defects enhanced photocatalytic properties of titania towards the deactivation of two bacteria species, and under artificial solar lamp irradiation.

The Influence of NHNO and NHClO on Porous Structure Development of Activated Carbons Produced from Furfuryl Alcohol.

The influence of NHNO and NHClO on the porous texture and structure development of activated carbons produced from a non-porous polymeric precursor synthesized from furfuryl alcohol has been studied. The non-doped counterparts were prepared and studied for comparison purposes. NHNO and NHClO-doped polymers were carbonized under N atmosphere at 600 °C, followed by CO activation at 1000 °C and the obtained carbon materials and activated carbons were thoroughly characterized.

Surface-Enriched Boron-Doped TiO Nanoparticles as Photocatalysts for Propene Oxidation.

A series of nanostructured boron-TiO photocatalysts (B--TiO-) were prepared by sol-gel synthesis using titanium tetraisopropoxide and boric acid. The effects of the synthesis variables, boric acid amount () and crystallization temperature (), on structural and electronic properties and on the photocatalytic performance for propene oxidation, are studied. This reaction accounts for the remediation of pollution caused by volatile organic compounds, and it is carried out at low concentrations, a case in which efficient removal techniques are difficult and costly to implement.

Chemical Activation of Lignocellulosic Precursors and Residues: What Else to Consider?

This paper provides the basis for understanding the preparation and properties of an old, but advanced material: activated carbon. The activated carbons discussed herein are obtained from "green" precursors: biomass residues. Accordingly, the present study starts analyzing the components of biomass residues, such as cellulose, hemicellulose, and lignin, and the features that make them suitable raw materials for preparing activated carbons.

Solid matter and soluble compounds collected from cigarette smoke and heated tobacco product aerosol using a laboratory designed puffing setup.

A laboratory setup recently designed has been used to perform puffing experiments in conditions similar to those of Health Canada Intense regime with the purpose of collecting and studying any particulate and/or soluble matter generated as a result of cigarette smoking or Heets use in an IQOS device. Smoke or aerosol can leave deposited matter in several parts of the setup, roughly resembling the interaction with the human body. Samples have been collected from different parts of the setup.

Design of carbon supports for metal-catalyzed acetylene hydrochlorination.

For decades, carbons have been the support of choice in acetylene hydrochlorination, a key industrial process for polyvinyl chloride manufacture. However, no unequivocal design criteria could be established to date, due to the complex interplay between the carbon host and the metal nanostructure. Herein, we disentangle the roles of carbon in determining activity and stability of platinum-, ruthenium-, and gold-based hydrochlorination catalysts and derive descriptors for optimal host design, by systematically varying the porous properties and surface functionalization of carbon, while preserving the active metal sites.

Photocatalytic Oxidation of Propane Using Hydrothermally Prepared Anatase-Brookite-Rutile TiO Samples. An In Situ DRIFTS Study.

Photocatalytic oxidation of propane using hydrothermally synthesized TiO samples with similar primary crystal size containing different ratios of anatase, brookite and rutile phases has been studied by measuring light-induced propane conversion and in situ DRIFTS (diffuse reflectance Fourier transform infrared spectroscopy). Propane was found to adsorb on the photocatalysts, both in the absence and presence of light. The extent of adsorption depends on the phase composition of synthesized titania powders and, in general, it decreases with increasing rutile and brookite content.

TiO₂ Modification with Transition Metallic Species (Cr, Co, Ni, and Cu) for Photocatalytic Abatement of Acetic Acid in Liquid Phase and Propene in Gas Phase.

The commercial P25 titania has been modified with transition metallic species (Cr, Co, Ni, and Cu), added by impregnation with aqueous solutions of the corresponding nitrates. The preparation procedure also includes a heat treatment (500 °C) in argon to decompose the nitrates, remove impurities and to strengthen the metal⁻TiO₂ interaction. The catalysts have been thoroughly characterized using N₂ adsorption, scanning electron microscopy (SEM), X-ray diffraction (XRD), UV-visible diffuse-reflectance spectroscopy (UV-vis DRS) and X-ray photoelectron spectroscopy (XPS), and have been tested in the aqueous phase decomposition of acetic acid and in the gas phase oxidation of propene, using an irradiation source of 365 nm in both cases.

Effect of the Preparation Method (Sol-Gel or Hydrothermal) and Conditions on the TiO₂ Properties and Activity for Propene Oxidation.

Since the two most commonly used methods for TiO₂ preparation are sol-gel (SG) and hydrothermal (HT) synthesis, this study attempts to compare both methods in order to determine which one is the most suitable to prepare photocatalysts for propene oxidation. In addition, this work studies how the concentration of the HCl used for hydrolysis of the TiO₂ precursor affects the properties of the obtained materials. Also, the effect of avoiding the post-synthesis heat-treatment in a selection of samples is investigated.

Spherical Activated Carbons with High Mechanical Strength Directly Prepared from Selected Spherical Seeds.

In the present manuscript, the preparation of spherical activated carbons (SACs) with suitable adsorption properties and high mechanical strength is reported, taking advantage of the retention of the spherical shape by the raw precursors. An easy procedure (carbonization followed by CO₂ activation) has been applied over a selection of three natural seeds, with a well-defined spherical shape and thermal stability: (RA), (OL), and (CI). After the carbonization-activation procedures, RA and CI, maintained their original spherical shapes and integrity, although a reduction in diameter around 48% and 25%, respectively, was observed.

Synthesis of TiO₂ with Hierarchical Porosity for the Photooxidation of Propene.

The elimination of volatile organic compounds (VOCs) at low concentration is a subject of great interest because these compounds are very harmful for the environment and human health. In this work, we have developed a synthesis methodology of TiO₂ that allows obtaining meso-macroporous materials with hierarchical porosity and with high thermal stability for their application as photocatalysts in the removal of VOCs, specifically propene. The materials synthesized in this work were characterized by Scanning electron microscope (SEM), Transmission electron microscopy (TEM), powder X-ray diffraction (XRD), Thermogravimetric Analysis (TG), and nitrogen adsorption.

Capacitance of KOH activated carbide-derived carbons.

Chemical activation of CDC leads to capacitance values in an organic electrolyte as high as 180 F/g, 30% larger than those of as-produced samples, due to the surface area and microporosity development occurring as a consequence of the activation.

Removal of odour-causing compounds using carbonaceous adsorbents/catalysts prepared from sewage sludge.

This paper discusses H(2)S, NH(3) and VOCs removal by sewage-sludge-derived materials with outstanding chemical and textural properties. These materials were obtained from different precursors using different chemical and thermal treatments. Results show that the H(2)S removal process entailed a catalytic conversion of H(2)S to S or SO(4) (2-) species.

A new generation of sludge-based adsorbents for H2S abatement at room temperature.

The present paper discusses H2S removal by a new generation of sewage-sludge-derived materials which are characterized by their outstanding textural properties when compared to previous materials obtained by pyrolysis and/or activation of similar precursors. Alkaline hydroxide activation was used to prepare adsorbents/catalysts covering a wide range of porosities (SBET values from 10 to 1300 m2 g(-1)). Our results outline that textural properties are important for H2S abatement.

High surface area materials prepared from sewage sludge-based precursors.

This paper focuses on physical activation (CO2) and chemical activation (H3PO4, NaOH and KOH) of sewage sludge-based precursors. Our results show that (i) a simple acid washing treatment leads to a significant increase in the adsorption capacity of some precursors; (ii) under the experimental conditions tested, CO2 physical activation and chemical activation with H3PO4 were ineffective for an efficient porosity development and (iii) choosing an appropriate protocol, it is possible to obtain highly porous materials (700-1700 m2 g(-1)) by chemical activation of sludge-based precursors with alkaline hydroxides. The efficiency of the chemical activation with NaOH or KOH is very much influenced by the method used for mixing the activating agent and the precursor.