Activity

  • Kamper Benson posted an update 2 days, 12 hours ago

    Semiconductor photocatalysis has been widely utilized to solve the problems of energy shortage and environmental pollution. Among the explored photocatalysts, nickel molybdate (NiMoO4) has revealed many advantages for photocatalytic applications, which include visible light absorption, low cost, environment-friendly, large surface area, good electrical conductivities, and tailorable band structure. However, the recombination of photogenerated carriers, which diminishes photocatalytic efficiency, has been held as a major hurdle to the widespread application of this material. To overcome this limitation, various surface modulations such as morphology control, doping of heteroatom, deposition of noble metal nanoparticles, and fabrication of composite structures have been explored in many published studies. This article comprehensively reviews the recent progress in the modulations of NiMoO4-based materials to improve the photocatalytic efficiency. The enhanced photocatalytic capabilities of NiMoO4-based materials are reviewed in terms of such applications as pollutant removal, disinfection of bacteria, and water splitting. The current challenges and possible future direction of research in this field are also highlighted. This comprehensive review is expected to advance the design of highly efficient NiMoO4-based materials for photocatalytic applications.Land use change has generally been considered a cause and consequence of environmental change. TP0184 Here, we interpreted the land cover in northern Southeast Asia (including parts of Myanmar, Thailand, Laos, Vietnam and China) year by year from 2000 to 2018 with the Google Earth Engine (GEE) platform. The results show that the areas of old growth forest, young growth forest and annual crops have changed dramatically in the study area. The average frequency of land use change was determined to be 5.4 times (that is, the land use changed every 3.4 years) by comparing the land use types in each year throughout the entire study period, and the frequency of land use change showed a significant agglomeration effect. In addition, there was a substantial difference between the land use change determined with an annual approach and that determined with the commonly used time-stage approach; time-stage land use change studies may overlook gradual change processes in land use change, which highlights the necessary of determining a suitable time period for studying land use change at the local scale. The results show that understanding land use volatility and agglomeration has become important to deepen the understanding of land use change and to help formulate land use policy.Human-induced changes in land and water resources adversely affect global hydrological regimes. Hydrological alteration of the natural flow regime is considered to have a significant damaging and widespread impact on river ecosystems and livelihoods. Therefore, understanding the hydrological alteration of rivers and the potential driving factors affecting such alterations are crucial to effective water resources management. This study analyses the impact of changes in land use, climate, and hydropower development on the hydrological regime of the Srepok River Basin in the Lower Mekong Region. The Lower Mekong Basin (LMB) in Southeast Asia is known for its agriculture, forests, fisheries, wildlife, and diverse natural ecosystems. Historical land use and climate change are quantified (utilising European Space Agency land cover and observed meteorological data) and correlated with the hydrological indicators using the Indicators of Hydrologic Alteration (IHA) software. Moreover, pre and post impacts on the hydrological regime by hydropower development are quantified using the Range of Variability Approach (RAV) in IHA software. The results reveal that land use, rainfall, and temperature affect different aspects of the hydrological regime, with corroborating evidence to support variation among the most correlated IHA and environmental flow component (EFC) parameters with the three drivers. The highest and lowest correlations among the IHA and EFC parameters under each driver are against land use (0.85, -0.83), rainfall (0.78, -0.54), and minimum and max temperatures (0.42, -0.47). Among the parameters, the fall rate has the most significant effect on hydrological alteration of all drivers. Hydropower development in the basin mostly affects the fall rate and reversal. Identifying the connection between these multiple drivers and hydrological alteration could help decision-makers to design more efficient and sustainable water management policies.Differential phase contrast (DPC) imaging in scanning transmission electron microscopy (STEM) allows for measuring electric and magnetic fields in solids on scales ranging from picometres to micrometres. The DPC technique mainly uses the direct beam, which is deflected by the electric and magnetic fields of the specimen and measured with a beam position sensitive detector. The beam deflection and thus the DPC signal is strongly influenced by specimen thickness, specimen tilt and lens aberrations. Understanding these influences is critical for a solid interpretation and quantification of contrasts in DPC images. To this end, the present study employs DPC-STEM image simulations of SrTiO3 [001] at atomic resolution to analyse the influence of lens aberrations, specimen tilt and thickness and also to give a guideline for the detection of parameters affecting the contrast by performing an analysis of associated scattergrams. Simulations are obtained using the multislice algorithm implemented in the Dr. Probe software with conditions corresponding to a JEOL ARM200F microscope equipped with an octa-segmented annular detector, but results should be similar for other microscopes. Simulations show that due to a non-rigid shift of the detected intensity distribution correct values of projected potentials of specimens thicker than one unit-cell cannot be determined. Regarding the impact of residual lens aberrations, it is found that the shape of the lens aberration phase function determines the symmetry and features in the DPC image. Specimen tilt leads to an elongation of features perpendicular to the tilt axis. The results are confirmed by comparing simulated with experimental DPC images of Si [110] yielding good agreement. Overall, a high sensitivity of DPC-STEM imaging to lens aberrations, specimen tilt and diffraction effects is evidenced.