Meng He,Xiaoyi Chen,Kui Cheng,Wenjian Weng,Huiming Wang
The topography at the micro-/nanoscale level and bioactive composition of material surfaces have been thought to play vital roles in their interactions with cells. However, it is still a challenge to further modify special topography with biodegradable composition or vice versa. In this study, TiO2 nanorod films covered with microscale-distributed Zn-containing calcium phosphate (Zn-CaP) were prepared, trying to create a micro-/nanoscale topography and Zn2+ release capability. MC3T3-E1 cells cultured on TiO2 nanorod film with sparsely distributed Zn-CaP (TiO2/S-ZCP) had significantly higher biological responses than those on the films with densely distributed Zn-CaP (TiO2/D-ZCP) and fully covered Zn-CaP (F-ZCP). TiO2/S-ZCP film was demonstrated to facilitate osteogenic differentiation much more strongly than F-ZCP and TiO2/D-ZCP films based on evaluations of ALP, related gene expressions, and extracellular matrix mineralization. The higher osteogenic differentiation on TiO2/S-ZCP film is ascribed to the micro-/nanoscale topography from Zn-CaP coverage promoting cell adhesion and filopodia extension, and inducing differentiation-orientation in the initial stage. And consequently Zn2+ release results in enhancement of differentiation. Therefore, we believe that better organization of the micro-/nanotopography and bioactive ion release on the surface would be a promising way to enhance osteogenic activity for orthopedic and dental implants.
Jiale Deng,Juan Gao,Mei Liu,Yanfen Wang,Lingcheng Zheng,Yang Li,Yin Liu
TiO2/SnS/MoS2 ternary nanorod arrays were synthesized on a fluorine-doped tin oxide (FTO) conductive glass by a successive hydrothermal method. The morphology, microstructure, optical properties, photodegradation activity, photoelectrochemical performance, and charge transport mechanism of TiO2/SnS/MoS2 were systematically studied. It was found that SnS and MoS2 with a narrow bandgap can facilitate light absorbance of TiO2/SnS/MoS2 heterostructures across the visible range, improving the utilization of sunlight. TiO2/SnS/MoS2 exhibits the maximum photodegradation rate (61.54%) for Rhodamine B (RhB) in 60 min with a pseudo-first-order rate constant (0.0122 min−1), which is about 5.16 times better than that of TiO2. As a photoanode, TiO2/SnS/MoS2 has the highest photocurrent (0.841 mA cm−2), which is approximately 8.32 times better than those of TiO2. The enhanced photocatalytic and photoelectrochemical performance of TiO2/SnS/MoS2 is ascribed to the Z-scheme mechanism determined by the detection of active species and the synergistic effect of SnS and MoS2 co-decoration.
The CsPbBr 3 perovskite solar cells (PSCs) based on carbon counter electrode (CCE) are promising because of the advantages including fabrication simplicity and excellent stability, but their power conversion efficiencies (PCE) are low due to interfacial carrier recombination as the direct contact of the CsPbBr 3 with electron transport materials (ETM). In this paper, PbTiO 3 shells were grown onto TiO 2 nanorods to form PbTiO 3 -coated TiO 2 scaffold layer via a two-step method. The presence of PbTiO 3 could promote crystallinity of the CsPbBr 3 perovskite film and inhibits interface recombination at the CsPbBr 3 /TiO 2 interface. Consequently, the carbon-based CsPbBr 3 solar cells with PbTiO 3 /TiO 2 scaffold layer achieves a high PCE of 7.28%, demonstrating an increase by 19.9% compared with the devices based on TiO 2 NRs. Moreover, the champion devices exhibited excellent stability in ambient air, with the PCE value remaining at 93% over 28 days.