In the last decades, photocatalysis has arisen as a solution to degrade emerging pollutants such as antibiotics. However, the reduced photoactivation of TiO2 under visible radiation constitutes a major drawback because 95% of sunlight radiation is not being used in this process. Thus, it is critical to modify TiO2 nanoparticles to improve the ability to absorb visible radiation from sunlight. This work reports on the synthesis of TiO2 nanoparticles decorated with gold (Au) nanoparticles by deposition-precipitation method for enhanced photocatalytic activity. The produced nanocomposites absorb 40% to 55% more radiation in the visible range than pristine TiO2, the best results being obtained for the synthesis performed at 25 °C and with Au loading of 0.05 to 0.1 wt. %. Experimental tests yielded a higher photocatalytic degradation of 91% and 49% of ciprofloxacin (5 mg/L) under UV and visible radiation, correspondingly. Computational modeling supports the experimental results, showing the ability of Au to bind TiO2 anatase surfaces, the relevant role of Au transferring electrons, and the high affinity of ciprofloxacin to both Au and TiO2 surfaces. Hence, the present work represents a reliable approach to produce efficient photocatalytic materials and an overall contribution in the development of high-performance Au/TiO2 photocatalytic nanostructures through the optimization of the synthesis parameters, photocatalytic conditions, and computational modeling.

The aim of our study is an improved level of geometrical design fidelity of LTCC microsystems by consideration of location-dependent shrinkage under free sintering conditions. To achieve this, the commercial low temperature co-fired ceramic (LTCC) systems: DuPont GT 951, DuPont 9k7 and Heraeus CT 702 have been investigated experimentally with special regard to the local lateral shrinkage over a 4 inch × 4 inch substrate typically used for the fabrication in multiple panels. Partially crystallizing LTCC materials reveal a significant local dependence of the lateral shrinkage. This dependence is introduced as a shrinkage field. Furthermore, we present an approach for shrinkage field approximation and forecasting. Applied to shrinkage allowance, it allows for minimizing the geometrical deviations after sintering from designed dimensions. Alternatively to a design adapted to the forecasted shrinkage field, local shrinkage deviations can be minimized by sintering for homogeneous shrinkage. Detailed analyses of the DuPont GT 951 system indicate a strong influence of the temperature profile during the free sintering on the shrinkage field. By utilizing this influence, a homogenous shrinkage field can be achieved for optimized heating rate and dwell time at the peak temperature 850 °C.

The aim of our study is a knowledge-based consideration of the inhomogeneous lateral shrinkage (shrinkage field) of commercial Low temperature co-fired ceramic (LTCC-) materials under free sintering conditions to improve the geometrical design fidelity and productions yield of system packages and microsystems fabricated in LTCC. Thus the phenomenological investigations of LTCC materials under various lamination and sintering conditions are presented. Deduced from this, feasible approaches for the compensation of the inhomogeneous shrinkages are introduced. Further thermal as well as thermomechanical analysis distinguish the origin of the shrinkage fields and enable the knowledge-based control of the shrinkage behavior in the design and fabrication process as well as in the material development