The effect of morphology and size on the photocatalytic properties of MoS2

Environmental remediation of hazardous pollutants using MXene-perovskite-based photocatalysts: A review

Photocatalysis utilizing semiconductors offer a cost-effective and promising solution for the removal of pollutants. MXene and perovskites, which possess desirable properties such as a suitable bandgap, stability, and affordability, have emerged as a highly promising material for photocatalytic activity. However, the efficiency of MXene and perovskites is limited by their fast recombination rates and inadequate light harvesting abilities. Nonetheless, several additional modifications have been shown to enhance their performance, thereby warranting further exploration. This study delves into the fundamental principles of reactive species for MXene-perovskites. Various methods of modification of MXene-perovskite-based photocatalysts, including Schottky junction, Z-scheme and S-scheme are analyzed with regard to their operation, differences, identification techniques and reusability. The assemblance of heterojunctions is demonstrated to enhance photocatalytic activity while also suppressing charge carrier recombination. Furthermore, the separation of photocatalysts through magnetic-based methods is also investigated. Consequently, MXene-perovskite-based photocatalysts are seen as an exciting emerging technology that necessitates further research and development.

Experimental and theoretical study of catalytic dye degradation and bactericidal potential of multiple phase Bi and MoS2 doped SnO2 quantum dots†

In the present study, different concentrations (1 and 3%) of Bi were incorporated into a fixed amount of molybdenum disulfide (MoS₂) and SnO₂ quantum dots (QDs) by co-precipitation technique. This research aimed to increase the efficacy of dye degradation and bactericidal behavior of SnO₂. The high recombination rate of SnO₂ can be decreased upon doping with two-dimensional materials (MoS₂ nanosheets) and Bi metal. These binary dopants-based SnO₂ showed a significant role in methylene blue (MB) dye degradation in various pH media and antimicrobial potential as more active sites are provided by nanostructured MoS₂ and Bi³⁺ is responsible for producing a variety of different oxygen vacancies within SnO₂. The prepared QDs were described via morphology, optical characteristics, elemental composition, functional group, phase formation, crystallinity, and d-spacing. In contrast, antimicrobial activity was checked at high and low dosages against Escherichia coli (E. coli) and the inhibition zone was calculated utilizing a Vernier caliper. Furthermore, prepared samples have expressed substantial antimicrobial effects against E. coli. To further explore the interactions between the MB and Bi/MoS₂–SnO₂ composite, we modeled and calculated the MB adsorption using density functional theory and the Heyd–Scuseria–Ernzerhof hybrid (HSE06) approach. There is a relatively strong interaction between the MB molecule and Bi/MoS₂–SnO₂ composite.

In the present study, different concentrations (1 and 3%) of Bi were incorporated into a fixed amount of molybdenum disulfide and SnO₂ quantum dots by co-precipitation technique. This research aimed to increase the efficacy of dye degradation and bactericidal behavior of SnO₂.

In situ preparation of 2D MoS2 nanosheets vertically supported on TiO2/PVDF flexible fibers and their photocatalytic performance

Two-dimensional (2D) MoS₂ nanosheets vertically supported on TiO₂/PVDF flexible fibers have been successfully synthesized by combining electrospinning with a low temperature hydrothermal method without acid. The morphology of the 2D MoS₂ nanosheets could be controlled by adjusting the experimental parameters. The loaded 2D MoS₂ nanosheets can not only broaden the light capture range of TiO₂, but also greatly inhibit the recombination rate of photogenerated electron-hole pairs. Due to the synergistic effect between MoS₂ and TiO₂, the photocatalytic rate for levofloxacin hydrochloride is about 40 times higher than that for MoS₂ only. Recycle experiments have proved the stability and reusability of TiO₂/PVDF@2D MoS₂ nanosheets. The mechanism is investigated by quenching experiments. The results show that the superoxide anion radical (•O₂ ^-), the hydroxyl radical (•OH) and the hole (h⁺) all have contributions to photocatalysis. This work widens the range of materials to synthesize the composites of 2D MoS₂ nanosheets and provides a new and gentle method for preparing flexible large-scale heterostructures for environmental protection.

Enhanced Lubrication and Photocatalytic Degradation of Liquid Paraffin by Hollow MoS2 Microspheres

Nowadays, with the rapid development of environmental protection awareness, the demand for the emergence of a green counterpart of lubricant additive plays a more and more important role in reducing friction and wear as the times require. In this paper, full-hollow and semihollow molybdenum disulfide (MoS₂) microspheres were prepared via a hydrothermal method and were characterized and confirmed by X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). According to our results, both fully hollow and semihollow MoS₂ microspheres possessed excellent lubrication-enhancing effects for liquid paraffin (LP), while full-hollow samples after friction provided better photocatalytic degradation properties than semihollow samples after friction. Related analysis indicated that curved layer opened structures with more rim and edge sites, bigger surface area, and narrower band gap made full-hollow MoS₂ samples achieve a better photocatalytic level. Thus, it was a sustainable solution for both lubrication-enhancing and photocatalytic degradation functions during different stages of the usage of lubricating oils, which suggests a potential strategy for achieving environmentally friendly developments.

Efficient visible light-induced degradation of rhodamine B by W(NxS1-x)2 nanoflowers

Here, W(N_xS_1−x)₂ nanoflowers were fabricated by simple sintering process. Photocatalytic activity results indicated our fabricated N-doped WS₂ nanoflowers shown outstanding photoactivity of degradating of rhodamine B with visible light. Which is attributed to the high separation efficiency of photoinduced electron–hole pairs, the broadening of the valence band (VB), and the narrowing of energy band gap. Meanwhile, our work provided a novel method to induce surface sulfur vacancies in crystals by introduing impurities atoms for enhancing their photodegradation.

Flower-like N-doped MoS2 for photocatalytic degradation of RhB by visible light irradiation

In this paper, the photocatalytic performance and reusability of N-doped MoS2 nanoflowers with the specific surface area of 114.2 m(2) g(-1) was evaluated by discoloring of RhB under visible light irradiation. Results indicated that the 20 mg fabricated catalyst could completely degrade 50 ml of 30 mg l(-1) RhB in 70 min with excellent recycling and structural stability. The optimized N-doped MoS2 nanoflowers showed a reaction rate constant (k) as high as 0.06928 min(-1) which was 26.4 times that of bare MoS2 nanosheets (k = 0.00262). In addition, it was about seven times that of P25 (k = 0.01) (Hou et al 2015 Sci. Rep. 5 15228). The obtained outstanding photocatalytic performance of N-doped MoS2 nanoflowers provides potential applications in water pollution treatment, as well as other related fields.