FlatChem最新文献

Recently, the utilization of heterogeneous photocatalysts has been proposed as an effective solution for environmental purification, as one of the solar energy conversion processes, under mild conditions. In this research, MnMoO₄·H₂O nanoparticles were anchored on tubular g-C₃N₄ (abbreviated as TGCN) by a one-pot hydrothermal route. The phase structure, electronic environment, spectroscopic characteristics, composition, morphology, surface area, and electrochemical properties of the resultant materials were explored using XRD, XPS, EDX, FESEM, HRTEM, FTIR, PL, photocurrent, EIS, and BET analyses. The photocatalytic activity of TGCN/MnMoO₄·H₂O (20 %) nanocomposite was 4.25, 5.36, 9.07, 12.4, and 8.84 times better than modified GCN, and 3.91, 2.77, 6.24, 10.9, and 6.82 times higher than MnMoO₄·H₂O in removals of tetracycline, rhodamine B, methylene blue, methyl orange, and fuchsine pollutants, respectively. The improved visible-light absorption and rapid charge migration/separation between TGCN and MnMoO₄·H₂O counterparts through S-scheme heterojunction route were the key reasons for the boosted photocatalytic performance. The biocompatibility of solution after decomposition of tetracycline via the growth of wheat seeds was verified. Finally, the stability of the binary TGCN/MnMoO₄·H₂O (20 %) heterostructure was measured by the stability test after four reuses.

Nowadays, the growing global population and increased industrialization have exacerbated water pollution, posing a significant environmental threat. To tackle this issue, there is an urgent need for effective catalysts to remove pollutants. This study developed a novel N-doped g-C₃N₄/Nd-doped ZnO (NZ) heterostructure using a green approach by incorporating pomegranate peel waste as a stabilizing and capping agent. Characterization techniques confirmed successful NZ nanohybrid preparation. The synthesized NZ displayed high photocatalytic activity in degrading methylene blue (MB) and tetracycline (TC) pollutants found in wastewater, achieving degradation efficiencies of 95.3 % and 98.3 %, respectively. Meanwhile, it demonstrated satisfactory photostability after five-cycle experiments. The radical trapping experiments revealed that superoxide (O₂⁻) and hydroxyl (OH) are the dominant active species and play an essential role in photocatalytic pollutant deterioration. Additionally, it exhibited suitable antimicrobial activity against Staphylococcus aureus and Vibrio cholerae bacterial strains. The enhanced performance is attributed to the abundant reaction sites of porous N-doped g-C₃N₄, the photo-redox capability of Nd-doped ZnO, and the efficient charge separation process in the Z-type heterojunction. This work advances sustainable and eco-friendly chemistry for the biosynthesis of organic/inorganic heterojunctions used in pollutant degradation and bacterial disinfection of wastewater.

Hydrogen production from water as renewable energy resource is vital to fulfil the huge energy demands without any hazardous environmental impact. Pursuing the efficient, durable and economical electrocatalyst other than benchmark expensive materials such as Pt, Ru, and Ir, for water electrolysis is a big challenge to produce the hydrogen as clean fuels. Here, we have successfully decorated nickel oxides nanoparticles over the carbon nanotubes covered by the graphene oxide layers (GO/NiO@CNTs/GO) using a facile hydrothermal method and utilized as electrocatalyst for electrochemical water splitting. The surface morphology and structure was assessed using a variety of analytical techniques, including scanning electron microscopy (SEM), energy dispersive X-rays spectroscopy (EDX) and X-ray diffraction (XRD). As prepared nanohybrid (GO/NiO@CNTs/GO) was utilized as multifunctional electrocatalyst to investigate the water electrolysis potential via different electrochemical techniques including linear sweep voltammetry (LSV), and cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and chronoamperometry. The fabricated electrode exhibited a lower overpotential of 236 mV and 208 mV at the standard current density of 10 mAcm⁻² under alkaline and acidic conditions, respectively. Enhanced double layer capacitance (C_dl) and reduced charge transfer resistance (R_ct) also showed the boosted performance for the hybrid materials with long term stability. The carbon based nanohybrid (GO/NiO@CNTs/GO) showed the promising potential having multifunctional characteristics including oxygen and hydrogen evolution reactions along with overall electrochemical water splitting.

The electrochemical energy conversion process must develop effective, long-lasting, and reasonably priced bifunctional electrocatalysts for the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). In this work, we present a simple, sustainable, economical, and scalable method for the preparation of stable and useful nickel nanoparticles on highly porous graphitic carbon doped with nitrogen. Direct pyrolysis followed by carbonization was used to create robust catalysts at different temperatures in an environment containing nitrogen (N₂). The carbon material generated at 600 °C (Ni@NPC-600) shows greater electrochemical efficiency when compared to other catalysts. The synthesized electroactive catalyst Ni@NPC-600 requires a less overpotential 280 mV (114 mV dec⁻¹) for OER and 151 mV (98 mV dec⁻¹) to conduct a HER at 10 mA cm⁻² in 1 M KOH. The active catalyst Ni@NPC-600 shows long-lasting robustness over 90 h with a current loss of <3.33 % and <4.9 % for OER and HER respectively. In addition, the overall water disintegration of Ni@NPC-600/NF//Ni@NPC-600/NF was achieved at 1.51 V with a continuous evolution of H₂ and O₂ at the cathode and anode respectively for approximately 150 h of prolonged robustness with a current reduction of < 4.6 %.

Incorporating iron nanoparticles into graphene oxide (GO) may enhance its potential for use in various applications. However, alterations to the GO structure could pose a risk to environmental organisms and should therefore be fully understood before their further use. In this paper, we prepared iron-doped graphene oxide from pure graphene oxide and two different iron sources with iron in two different oxidation states. Prepared samples were characterized in detail by SEM, EDS, XRF, Raman spectroscopy, XPS, and TEM. In the next step, these samples were subjected to ecotoxicological evaluation in three model organisms: mustard Sinapis alba, freshwater algae Desmodesmus subspicatus, and saltwater crustaceans Artemia salina. Our results showed a stimulatory effect of iron-doped GO on S. alba seeds and a modest degree of growth inhibition for D. subspicatus when compared to pure GO at a concentration of 100 mg/L. In the case of A. salina, mortality was observed at a concentration of 10 mg/L for all tested nanoparticles. However, the iron-doped nanoparticles exhibited a more than twofold decrease in mortality. Our findings suggest that iron-doped GO have a reduced toxicity compared to pure GO, but further research is necessary to enhance the understanding of their behaviour in the environment.

The Ti₃C₂T_x MXene has ignited a wave of excitement in the world of materials science due to its immense potential for diverse applications. However, a deeper understanding of the synthesis processes involved is crucial to unlock their potential. Here we review the various techniques for producing Ti₃C₂T_x MXene, covering everything from precursor selection to etching-exfoliation and intercalation-delamination steps. Furthermore, we also explore the oxidation stability of Ti₃C₂T_x and propose a reaction mechanism to help shed light on this critical aspect of Ti₃C₂T_x MXene. This review begins with the bibliography studies on Ti₃C₂T_x and then delves into the principle behind the chemical etching process. Followed by various etching strategies used for Ti₃C₂T_x synthesis and the impact of individual etching parameters on successful synthesis protocols. Finally, we address the challenges that still need to be overcome to fully realize the potential of Ti₃C₂T_x and highlight the exciting possibilities for its future development. We aim to inspire further research into this cutting-edge material and encourage the synthesis of Ti₃C₂T_x MXene with even more outstanding performance and a more comprehensive range of applications.

Graphene quantum dots (GQDs) are nanometer-sized fragments of graphene with unique characters, which make them as new interesting application candidates in the fields of chemical, environmental and energy engineering. In this paper, the four nitropyrenes with different nitration degree, such as mononitropyrene, dinitropyrene, trinitropyrene and tetranitropyrene, were successfully synthesized and used to rationally construct corresponding graphite phase quantum dots named GQD(1), GQD(2), GQD(3) and GQD(4) in turn. Subsequently, the relationship between the structure and photocatalytic activity of different intermediates for the preparation of GQD were systematically studied. Degree of polymerization and lateral size of GQDs prepared with different intermediates significantly affected their photocatalytic performance. Through comparision of the photocatalytic water splitting reaction of four GQDs, it was found that GQD(4) had the best photocatalytic efficiency among four GQDs.