Laser-synthesized TiN-based nanoparticles as novel efficient electrostatic nanosorbent for environmental water cleaning

Bahamondes Lorca V.A., Ávalos-Ovando O., Sikeler C., Ijäs H., Santiago E.Y., Skelton E., Wang Y., Yang R., Cimatu K.L., Baturina O., Wang Z., Liu J., Slocik J.M., Wu S., Ma D., et. al.

Tahir, Concas G.C., Gisbert M., Cremona M., Lazaro F., Maia da Costa M.E., De Barros S.D., Aucélio R.Q., Pierre T.S., Godoy J.M., Mendes D., Mariotto G., Daldosso N., Enrichi F., Cuin A., et. al.

Over the last decade, the CO2 reduction reaction (CO2RR) has been increasingly exploited for the synthesis of high‐value raw materials in gaseous or liquid form, although no examples of CO2 fixation in nanoparticle systems have been demonstrated. Herein, CO2 fixation into solid nanomaterials by laser synthesis and processing of gold colloids in water, traditionally considered a green approach leading to ligand‐free nanoparticles without the formation of by‐products, is reported. If carbon monoxide‐rich gold nanoparticles are observable even after synthesis in deionized water, the presence of CO2 derivatives in alkaline water environment leads to C2 and C3 coupling with the production of carboxylic acids as a typical CO2RR fingerprint. While laser processing of preformed gold colloids is selective for C2 coupling, both C2 and C3 coupling to lactic acid are observed during pulsed laser ablation of a gold target. In the latter case, it is demonstrated that it is possible to synthesize photoluminescent organometallic nanocomposites in the blue spectral region with a quantum yield of about 20% under adequate experimental conditions. In this research, new pathways are offered to be explored in energetics, photonics, catalysis, and synthesis at the nanoscale.

Lin H., Buerki-Thurnherr T., Kaur J., Wick P., Pelin M., Tubaro A., Carniel F.C., Tretiach M., Flahaut E., Iglesias D., Vázquez E., Cellot G., Ballerini L., Castagnola V., Benfenati F., et. al.

Obayomi K.S., Lau S.Y., Danquah M.K., Zhang J., Chiong T., Meunier L., Gray S.R., Rahman M.M.

Water-soluble dyes are a common problem in wastewater treatment, requiring highly efficient methods for removal. In this study, novel sustainable adsorbents made from graphene-oxide (GO) and other materials, such as eggshell-derived calcium oxide nanoparticles (CaONPs-ES), fish bone calcium oxide nanoparticles (CaONPs-FB), and durian shell activated carbon (DSAC) were synthesized, characterized, and demonstrated for soluble dye removal from wastewater. Fermented maize grain extract (MES) was used as a green cross-linker in the synthesis process. The resulting nanocomposites, [email protected]/DSAC and [email protected]/DSAC, showed promising adsorption capabilities for methylene blue (MB) dye removal from aqueous environments. The prepared nanocomposites ([email protected]/DSAC and [email protected]/DSAC) were characterize using state-of-art instrumental techniques. The BET measurement revealed that the nanocomposites surface areas were enhanced due to the cross-linking phenomenon, improving their adsorption capability towards MB dye treatment. The adsorption data of [email protected]/DSAC and [email protected]/DSAC was well fitted to the Harkins-Jura and Freundlich models, respectively. The maximum sorption capacities of [email protected]/DSAC and [email protected]/DSAC were 1274.5 and 689.7 mg/g, respectively. The MB dye removal mechanism was driven by π-π interaction, hydrogen bonding, electrostatic attraction and physical interactions and the adsorption process of the nanocomposites followed pseudo-second-order kinetics. The adsorptive performance of the nanocomposites was stable, showing ~96.45 % and ~85.18 % after 10 successive cycles for [email protected]/DSAC and [email protected]/DSAC respectively. Cost evaluation revealed that bulk synthesis of [email protected]/DSAC and [email protected]/DSAC nanocomposites is cost-effective for treating large quantities of MB contaminated water and other potential dyes as well. Finally, the independent and synergetic contributions between pH, adsorbent dosage and temperature on MB removal by [email protected]/DSAC and [email protected]/DSAC were studied and optimized by central composite design (CCD) an aspect of the response surface methodology (RSM). Finally, this study suggests that the novel green cross-linking approach has a significant impact in enhancing the adsorptive performances of the developed nanocomposites to effectively capture MB from aqueous environment.

Hendrix Y., Rauwel E., Nagpal K., Haddad R., Estephan E., Boissière C., Rauwel P.

ZnO is an effective photocatalyst applied to the degradation of organic dyes in aqueous media. In this study, the UV-light and sunlight-driven photocatalytic activities of ZnO nanoparticles are evaluated. A handheld Lovibond photometer was purposefully calibrated in order to monitor the dye removal in outdoor conditions. The effect of ZnO defect states, i.e., the presence of zinc and oxygen defects on the photocatalytic activity was probed for two types of dyes: fuchsin and methylene blue. Three morphologies of ZnO nanoparticles were deliberately selected, i.e., spherical, facetted and a mix of spherical and facetted, ascertained via transmission electron microscopy. Aqueous and non-aqueous sol-gel routes were applied to their synthesis in order to tailor their size, morphology and defect states. Raman spectroscopy demonstrated that the spherical nanoparticles contained a high amount of oxygen vacancies and zinc interstitials. Photoluminescence spectroscopy revealed that the facetted nanoparticles harbored zinc vacancies in addition to oxygen vacancies. A mechanism for dye degradation based on the possible surface defects in facetted nanoparticles is proposed in this work. The reusability of these nanoparticles for five cycles of dye degradation was also analyzed. More specifically, facetted ZnO nanoparticles tend to exhibit higher efficiencies and reusability than spherical nanoparticles.

Zhao B., Zhao Y., Liu P., Men Y., Pan Y.

Water pollution caused by dye is a serious challenge. Herein, we use a novel discharge process to functionalize carbon nanotube (CNT) by COOH groups to form CNT30 for removing methyl red (MR) from water. By pristine CNT, 75% MR is removed in 60 min, with an adsorption capacity of 68.44 mg g -1 . By CNT30, 85% MR is fast removed in only 5 min, and the removal efficiency reaches to 95% after 30 min, with an adsorption capacity of 80.33 mg g -1 . Thus, a higher MR removal efficiency is achieved in a much shorter time on CNT30. Moreover, CNT30 has an outstanding reusability, with the MR removal efficiency decreasing by only 7% after ten cycles. The COOH groups on CNT30 improve the hydrophilicity of CNT30, thus promoting the interaction of MR in water with CNT30. The hydrogen bonding and electrostatic interaction of MR with the COOH groups on CNT30 could be the force to drive MR adsorption on CNT30. The higher COOH content could be the origin for the better performance of CNT30 in removing dye from water. The discharge process developed herein is operated in O 2 , without using harmful substances, and the COOH content on CNT can be efficiently tuned by simply changing discharge time. This is different from the chemical modification widely used to functionalize CNT by strong oxidants, e.g. , HNO 3 . The present work is of great significance to realize green construction of materials for more efficiently removing dye from water. • COOH-rich carbon nanotubes are synthesized for fast removing dye from water. • By using the COOH-rich carbon nanotubes, 85% dye is removed in only 5 min. • The COOH-rich carbon nanotubes show superior reusability in a 10-cycle experiment. • The COOH groups on carbon nanotubes provide more active sites for dye removal.

Sankar Sana S., Haldhar R., Parameswaranpillai J., Chavali M., Kim S.

Organic dyes are a severe threat to aquatic life. Most dyes are toxic, non-biodegradable, and likely carcinogenic. Dyes are usually removed from water via adsorption using adsorbents like wood, seaweed, algae, etc. However, traditional treatment methods are ineffective to an extent. Nanoparticles have emerged as excellent materials for dye removal due to their superb surface properties and chemical reactivity. Many different adsorbents are used today; one example is nanocomposites with embedded silver nanoparticles. In nanocomposites, silver nanoparticles embedded on graphene oxide sheets, carbon nanotubes, cellulose, orange peel, biopolymers, etc., are reported. The solid and hydrogel-based metallic and bimetallic silver nanoparticle-based nanocomposites are successful enough to degrade dyes. These nanocomposites had high reusability, stability, high surface area, tunable properties, selectivity, cost-effectiveness, excellent processability, and recyclability. For instance, AgNPS/alginate composites reported high reusability with recyclability up to 25 times. This article sheds light on the use of biopolymer composites with embedded Ag-NPs for effective dye removal. Various preparation methods as well as the kinetics of the reaction are also discussed.

Chouaybi I., Ouassif H., Bettach M., Moujahid E.M.

• Hydrocalumite intercalated with chloride (Ca-Al-Cl) was synthesized via co-precipitation method at constant pH. • The adsorption equilibrium of AR97 dye on the HC material was reached after 20 min of contact, with a maximum adsorption capacity of 1126.62 mg.g -1 at 293K. • Adsorption data rightly follow the pseudo second-order kinetic model and Langmuir isotherm model. • The adsorption process was physisorption, spontaneous, and exothermic. Owing to their structure and exceptional physical and chemical properties, layered double hydroxides (LDH) are highly recommended for many applications, such as catalysis, medicine, additives in polymers, and environmental treatments. In this framework, hydrocalumite (Ca-Al-Cl) type LDH was prepared via a co-precipitation procedure at constant pH to remove the acid red 97 dye (AR97). The hydrocalumite (HC) material formed was characterized by FTIR spectroscopy, X-ray powder diffraction, scanning electron microscopy (SEM), energy-dispersive X-Ray spectroscopy (EDS), BET-BJH, and inductively coupled plasma atomic emission spectroscopy (ICP-OES). The adsorption capacity of the prepared HC material was investigated under different experimental conditions using AR97 as an anionic dye. This material has shown good performance and exceptional efficiency for AR97 dye adsorption. The pseudo-second order model is more effective in explaining the adsorption kinetics of AR97 dye/HC; the equilibrium has been achieved after 20 min of contact. Isothermal studies confirmed that the adsorption data follows the Langmuir model with a maximum monolayer coverage of Q e = 1126.62 mg.g -1 . The adsorption process was physisorption, spontaneous and exothermic. Based on these promising results, it can be considered that hydrocalumite material has great efficiency in removing anionic dyes from wastewater.

Oladoye P.O., Ajiboye T.O., Omotola E.O., Oyewola O.J.

One of the popular cationic dyes that is environmentally persistent, toxic, carcinogenic and mutagenic is methylene blue (MB) dye. It is commonly applied as synthetic dye for dyeing fabrics in clothing and textile industries and also for dyeing papers and leathers. Sequel to the magnitude of industrial usage, a large volume of methylene blue dye containing wastewater is discharged into groundwater and surface water. At doses more than 5 mk/kg, the monoamine oxidate inhibitory characteristics of MB dye can induce fatal serotonin toxicity in human, apart from being a threat to fauna in aquatic ecosystem. Thus, it is highly imperative to eliminate MB dye from wastewaters. A number of different removal strategies have been reported in literature for treating methylene blue dye wastewater. In this state-of-the-art review, about 240 review and/or research published articles on methods for methylene blue dye wastewater decontamination or decontamination strategies were chosen for evaluation. This synthesis also discussed the various toxicities linked to MB dye. The assessment of elimination methods revealed that chemical removal methods (photochemical and non-photochemical) could generate secondary pollutants while biological methods are characterized with sensitivity of enzyme to pH. These drawbacks limit their industrial full-scale applications while adsorption technology was found to offer merits over others. The review comprehensively discussed each of these techniques while gaps and/or areas for future research are highlighted. • Adsorption technology needs in-depth study in the area of fixed bed column adsorption. • Methylene blue wastewater treatment should consider the impact of co-existence with other pollutants. • Industrial applications of the agro-waste-adsorbents should be explored. • The range of optimum pH for adsorption of methylene blue is 6–8.

Popov A.A., Tikhonowski G.V., Shakhov P.V., Popova-Kuznetsova E.A., Tselikov G.I., Romanov R.I., Markeev A.M., Klimentov S.M., Kabashin A.V.

Owing to a strong photothermal response in the near-IR spectral range and very low toxicity, titanium nitride (TiN) nanoparticles (NPs) synthesized by pulsed laser ablation in liquids (PLAL) present a novel appealing object for photo-induced therapy of cancer, but the properties of these NPs still require detailed investigation. Here, we have elaborated methods of femtosecond laser ablation from the TiN target in a variety of liquid solutions, including acetonitrile, dimethylformamide, acetone, water, and H2O2, to synthesize TiN NPs and clarify the effect of liquid type on the composition and properties of the formed NPs. The ablation in all solvents led to the formation of spherical NPs with a mean size depending on the liquid type, while the composition of the NPs ranged from partly oxidized TiN to almost pure TiO2, which conditioned variations of plasmonic peak in the region of relative tissue transparency (670–700 nm). The degree of NP oxidation depended on the solvent, with much stronger oxidation for NPs prepared in aqueous solutions (especially in H2O2), while the ablation in organic solvents resulted in a partial formation of titanium carbides as by-products. The obtained results contribute to better understanding of the processes in reactive PLAL and can be used to design TiN NPs with desired properties for biomedical applications.

Jabbar K.Q., Barzinjy A.A., Hamad S.M.

Nanotechnology provides the ability to manipulate materials at the nanoscale within desired properties and specific functions. This allows the material to be controlled and used in many application fields. The main area among these application domains is the environmental applications including the wastewater treatment . This area, precisely, can be divided into: treatment and remediation, sensing and detection and pollution control . Iron oxide nanoparticles have been studied in depth in many fields due to the advantages offered by this material over other materials. This wide use of iron oxide nanoparticles is more likely due to; low cost, separation by means of external magnetic fields, high surface area and high adsorption capacity. In addition, within the available standard techniques of separation it is not easy to treat crude oil in water. Thus, iron oxides nanoparticles can be used as coagulant in coagulation and flocculation procedure to remove oil droplets from oilfield produced water. Within this context and to highlight the importance of this topic in this research, the current study aims to contribute through a bibliographic review, within the available literature, the role of iron oxide nanoparticles in wastewater treatment. Based on the present study, it is possible to distinguish the different approaches and methods proposed to obtain iron oxide nanoparticles as well as their various applications, explicitly, the focus has been on wastewater treatment and supply technologies. Thus, the novelty of this study is utilizing iron oxides nanoparticles, since the separation process is simple via an external magnetic fields. Also, iron oxides nanoparticles possess high surface area, high pollutant adsorption capacity and have compatibility for functionalization by chemical groups and selecting organic compounds. Accordingly, this investigation is anticipated to contribute to the production bibliography about this theme and clarify the use of materials in nanoscale for wastewater treatments.

Lan D., Zhu H., Zhang J., Li S., Chen Q., Wang C., Wu T., Xu M.

Organic dyes, a type of high toxic and carcinogenic chemicals that present severe threats to human and aquatic life, are the most commonly seen organic pollutants in wastewater of industries such as textile, rubber, cosmetic industry etc. Various techniques for the removal of dyes are compared in this review. Adsorption has proven to be a facile and promising approach for the removal of dyes in wastewater. This work focuses on the latest development of various porous materials for the adsorption of organic dyes. The characteristics, functionalization and modification of different porous materials are also presented. Furthermore, adsorption behaviors and mechanism of these adsorbents in the adsorption of organic dyes are critically reviewed. Finally, challenges and opportunities for future research in the development of novel materials for the highly efficient removal of dyes are proposed.

Yu S., Pang H., Huang S., Tang H., Wang S., Qiu M., Chen Z., Yang H., Song G., Fu D., Hu B., Wang X.

Among many separation membranes reported to date, the favorable polymer affinity and unique physio-chemical performances of metal-organic frameworks (MOFs) including ultra-high surface area, regular and highly controlled porosity have drawn widespread attention in industrial and academic communities. In this comprehensive review, the developmental timeline of MOF containing membranes for water treatment were clarified. The removal efficiencies, elimination mechanisms, as well as possible influencing factors of various MOF containing membranes that applied to water treatment were systematically summarized. The excellent removal performances of MOF containing membranes for various pollutants were determined by the size-exclusion, π-π stacking interaction, electrostatic interaction, hydrogen bonding and so on. Since the progress of engineered MOF containing membranes for practical wastewater treatment applications lags, we further analyzed the potential environmental application of MOF containing membranes from four aspects (stability of MOFs, antifouling performance of membranes, compatibility between MOF fillers and polymer matrix, dispersity of MOF nanoparticles in matrix), hoping to provide some meaningful insights.

Tikhonowski G.V., Popova-Kuznetsova E.A., Aleshchenko Y.A., Klimentov S.M., Kabashin A.V., Popov A.A.

The effect of oxygen existing in an ablation medium during synthesis of titanium nitride (TiN) nanoparticles (NPs) by pulsed laser ablation in liquid (PLAL) on colloidal stability of obtained solutions was studied. It was shown that an increase in the oxygen content both incorporated in liquid molecules and in the form of dissolved gas increases the colloidal stability of synthesized NPs. The results obtained extend the range of available methods for developing new nanomaterials due to control of colloidal stability of laser-synthesized NPs.

Thabet R.H., Fouad M.K., Ali I.A., El Sherbiney S.A., Tony M.A.

The wide application of reactive dyes in textile manufacturing has posed a threat to the ecological system and human beings, therefore their use attracted increase attention. Magnetite is one of ub...