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In this study, TiO2/P, K-containing grapefruit peel biochar (TiO2/P, K-PC) composites were synthesized in situ biomimetically using grapefruit peel as the bio-template and carbon source and tetrabutyl titanate as the titanium source. This was achieved using the two-step rotary impregnation–calcination method. Adjusting the calcination temperature of the sample in an air atmosphere could regulate the mass ratio of TiO2 to carbon. The prepared samples were subjected to an analysis of their compositions, structures, morphologies, and properties. It demonstrated that the prepared samples were complexes of anatase TiO2 and P, K-containing carbon, with the presence of graphitic carbon. They possessed a unique morphological structure with abundant pores and a large surface area. The grapefruit peel powder played a crucial role in the induction and assembly of TiO2/P, K-PC composites. The sample PCT-400-550 had the best photocatalytic activity, with the degradation rate of RhB, MO, and MB dye solutions reaching more than 99% within 30 min, with satisfactory cyclic stability. The outstanding photocatalytic activity can be credited to its unique morphology and the efficient collaboration between TiO2 and P, K-containing biochar. [ABSTRACT FROM AUTHOR]

Soil moisture factor is one of the important parameters in the study of wind and sand fixation functions of ecosystems. Traditional methods often use potential evaporation, rainfall, and irrigation observed by meteorological stations to estimate soil moisture, which has significant limitations in terms of spatial continuity and data availability. Based on the development of remote sensing technology in soil moisture detection, we selected four remote sensing indicators for soil moisture (MODIS evapotranspiration ratio method, SMAP soil moisture ratio method, visible shortwave infrared drought index method, and remote sensing humidity index method) to improve the estimation of soil moisture factor in the modified wind erosion equation model (RWEQ), and used the improved algorithm to analyze the spatiotemporal variations and driving factors of wind prevention and sand fixation services in the northwest region of Liaoning Province from 2001 to 2021. The results showed that the MODIS evapotranspiration ratio method had the highest correlation with traditional meteorological methods in calculating soil moisture. The formula obtained by fitting the two could be used to improve the calculation of soil moisture factor in the RWEQ model. From 2001 to 2021, the wind prevention and sand fixation capacity in the northwest region of Liaoning Province showed strong spatial distribution characteristics in the northern and eastern regions, while weak in the central and western regions. According to Mann-Kendall trend testing, 72.7% of the regions in northwest Liaoning Province were showing an upward trend in their ability to prevent wind and fix sand. The application of geographic detector models for driving factor analysis showed that the change in wind and sand fixation capacity was a process of multi-pie factors interacting with each other, greatly influenced by soil type, annual wind speed, and economic development level. Moreover, the interaction between various driving factors had a higher impact on wind and sand fixation than that of single factors. The results could improve the RWEQ model estimation and provide technical support for the long-term analysis of ecological function formation mechanisms and driving forces in the northwest region of Liaoning. [ABSTRACT FROM AUTHOR]

Zero-dimensional environmentally friendly carbon quantum dots (CQDs) combined with two-dimensional materials have a wide range of applications in optoelectronic devices. We combined steady-state and transient absorption spectroscopies to study the energy transfer dynamics between CQDs and molybdenum disulfide (MoS2). Transient absorption plots showed photoinduced absorption and stimulated emission features, which involved the intrinsic and defect states of CQDs. Adding MoS2 to CQDs solution, the lowest unoccupied molecular orbital of CQDs transferred energy to MoS2, which quenched the intrinsic emission at 390 nm. With addition of MoS2, CQD-MoS2 composites quenched defect emission at 490 nm and upward absorption, which originated from another energy transfer from the defect state. Two energy transfer paths between CQDs and MoS2 were efficiently manipulated by changing the concentration of MoS2, which laid a foundation for improving device performance. [ABSTRACT FROM AUTHOR]

The charge and energy transfer dynamics in colloidal CdSeTe/ZnS quantum dots (QDs)/monolayer molybdenum disulfide (MoS2) heterostructures have been investigated by time-resolved single-dot photoluminescence (PL) spectroscopy. A time-gated method is used to separate the PL photons of single QDs from the PL photons of monolayer MoS2, which are impossible to be separated by the spectral filter due to their spectral overlap. It is found that the energy transfer from MoS2 to single QDs increases the exciton generation of the QDs by 37.5% and the energy transfer from single QDs to MoS2 decreases the PL quantum yield of the QDs by 66.9%. In addition, it is found that MoS2 increases the discharging rate of single QDs by 59%, while the charging rate remains unchanged. This investigation not only provides valuable insight into the exciton generation and recombination at the single-dot level across such hybrid 0D–2D interfaces but also promotes the application of the hybrid system in various optoelectronic devices. [ABSTRACT FROM AUTHOR]

In this study, microcapsules containing waste oil as rejuvenator were synthetized and characterized to enhance the self-healing ability of asphalt. Chemical structure, thermal stability, and micro morphology of microcapsules were described by Fourier Transform infrared spectroscopy, thermogravimetric analysis, and scanning electron microscope. Self-healing effect of asphalt samples was captured through fatigue-healing test. Results show that microcapsules were fabricated spherical and intact with agglomerated layers, and it has satisfied thermal stability. Addition of microcapsules hardly impacted viscosity of asphalt binder and accelerated the self-healing of asphalt with respect to complex modulus and fatigue life. [ABSTRACT FROM AUTHOR]

Grapefruit peel possesses a porous structure and a significant specific surface area. In this study, we introduce an innovative and eco-friendly approach for synthesizing porous TiO 2 . This was accomplished by employing grapefruit peel as a bio-template and tetrabutyl titanate as the precursor, utilizing a two-step rotary impregnation-calcination process. The TiO 2 faithfully reproduced the structural characteristics of the grapefruit peel across different scales, simultaneously incorporating C, P, K elements from the original grapefruit peel into the final samples. The fabricated samples were analyzed using XRD, XPS, SEM, TEM, BET, and UV-vis DRS. The results showed that the TiO 2 displays an anatase phase, and possesses a high specific surface area. The investigation of photocatalytic performance demonstrated that the CPK-TiO 2 -10 sample exhibited outstanding photocatalytic activity against Rhodamine B (RhB) solution, achieving complete degradation within 60 minutes. Additionally, the total organic carbon (TOC) removal rate reached 91.34% after 60 minutes of irradiation. The sample maintained a high degradation efficiency, even after five recycling cycles. This exceptional performance can be attributed to its porous structure, enriched with pores and a larger surface area, as well as the beneficial effects of doping with C, P, K elements in TiO 2 ., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

The charge and energy transfer dynamics in colloidal CdSeTe/ZnS quantum dots (QDs)/monolayer molybdenum disulfide (MoS 2 ) heterostructures have been investigated by time-resolved single-dot photoluminescence (PL) spectroscopy. A time-gated method is used to separate the PL photons of single QDs from the PL photons of monolayer MoS 2 , which are impossible to be separated by the spectral filter due to their spectral overlap. It is found that the energy transfer from MoS 2 to single QDs increases the exciton generation of the QDs by 37.5% and the energy transfer from single QDs to MoS 2 decreases the PL quantum yield of the QDs by 66.9%. In addition, it is found that MoS 2 increases the discharging rate of single QDs by 59%, while the charging rate remains unchanged. This investigation not only provides valuable insight into the exciton generation and recombination at the single-dot level across such hybrid 0D-2D interfaces but also promotes the application of the hybrid system in various optoelectronic devices.