Fundamentals and challenges for indirect and direct photocatalytic conversion of plastic wastes into valuable fuels
Peer-Reviewed Publication
Updates every hour. Last Updated: 28-Jun-2025 02:10 ET (28-Jun-2025 06:10 GMT/UTC)
Nowadays, plastic wastes have seriously endangered human health and ecological safety. Recycling plastics is a promising ap-proach to achieve multiple uses of carbon resources. In this review, photocatalysis is introduced for the conversion of plastics into various valuable chemicals. The state-of-the-art photocatalytic techniques for plastics conversion are divided into two categories of direct and indirect photoconversion. Researchers summarize in detail the photocatalytic small organic molecules conversion from polyeth-ylene terephthalate (PET), polylactic acid (PLA) and polyethylene (PE) through the alkaline-assistant and hydrothermal pretreat-ments. Then, they overview the effective strategies of direct photoconverting PE, PLA and polyvinyl chloride into chemicals via the two-step process, amination strategy, and single reactive oxygen species-assistant strategy. Finally, they present some outlooks of the current challenges and propose some potential solutions in the future.
To enhance existing strategies for controlling the Aedes aegypti mosquito, geoinformation scientist Dr Steffen Knoblauch has created a high-resolution environmental suitability map for Rio de Janeiro (Brazil) that can help identify areas most conducive to breeding. It is based on advanced geospatial big data methods – leveraging openly available geodata such as satellite imagery, street view images, and climate data – that the researcher developed at Heidelberg University’s Interdisciplinary Center for Scientific Computing (IWR) and at HeiGIT (Heidelberg Institute for Geoinformation Technology).
On June 5 and 6, 2025, the University of Stuttgart hosted a high-profile event honoring the legacy of Frei Otto - architect, Pritzker Prize winner and master of lightweight construction. Under the title "Frei Otto 100 – The Spirit of Lightweight Construction," international guests from science, architecture, and society gathered at the Institute of Lightweight Structures and Conceptual Design (ILEK) to celebrate the visionary thinking of one of the 20th century’s most influential designers – at the very place where Otto once worked. Frei Otto is considered a pioneer of ecological and experimental building.
A new AI tool to predict the spread of infectious disease outperforms existing state-of-the-art forecasting methods.
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Biological cells exhibit nearly transparent characteristics with weak absorption properties in the visible light spectrum, resulting in extremely low optical contrast between cells and the surrounding medium under traditional bright-field microscopy. To enhance imaging contrast, conventional methods rely on chemical staining or fluorescent labeling, introducing exogenous absorption/fluorescence probes to visualize cellular structures. However, these approaches suffer from drawbacks such as phototoxicity, photobleaching, and poor biocompatibility, severely limiting long-term dynamic observation of living cells. Quantitative phase imaging (QPI) utilizes the inherent physical property of cellular phase (thickness) as an endogenous “probe”, resolving cellular thickness, refractive index, and 3D topography with nanoscale accuracy. It provides a new avenue for dynamic observation of living cells and nanoscale biological studies.
As a significant branch of QPI technology, differential phase contrast (DPC) has attracted considerable attention due to its advantages of being non-interferometric and low-cost. However, its theoretical framework relies on the “weak object approximation”, linking intensity images to sample phase through a linear model. This simplified model introduces two fundamental limitations. First, the phase reconstruction result is highly dependent on the precise modeling of the phase transfer function (PTF) under an ideal pupil. In practical optical systems, however, wavefront aberrations couple with the sample phase, leading to significant reconstruction errors. Second, the conventional half-circle illumination suffers from the problem of PTF response cancellation, resulting in the loss of low-frequency phase information and making it difficult to accurately reconstruct the fine structure of weak phase objects. These limitations significantly compromise the robustness of DPC in non-ideal optical environments and restrict its practical applicability in frontier biological research, such as cellular morphology characterization and tracking of subcellular dynamic processes.