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Abstract Bi3TiNbO9, a layered ferroelectric photocatalyst, exhibits great potential for overall water splitting through efficient intralayer separation of photogenerated carriers motivated by a depolarization field along the in-plane a-axis. However, the poor interlayer transport of carriers along the out-of-plane c-axis, caused by the significant potential barrier between layers, leads to a high probability of carrier recombination and consequently results in low photocatalytic activity. Here, we have developed an efficient photocatalyst consisting of Bi3TiNbO9 nanosheets with a gradient tungsten (W) doping along the c-axis. This results in the generation of an additional electric field along the c-axis and simultaneously enhances the magnitude of depolarization field within the layers along the a-axis due to strengthened structural distortion. The combination of the built-in field along the c-axis and polarization along the a-axis can effectively facilitate the anisotropic migration of photogenerated electrons and holes to the basal {001} surface and lateral {110} surface of the nanosheets, respectively, enabling desirable spatial separation of carriers. Hence, the W-doped Bi3TiNbO9 ferroelectric photocatalyst with Rh/Cr2O3 cocatalyst achieves an efficient and durable overall water splitting feature, thereby providing an effective pathway for designing excellent layered ferroelectric photocatalysts.

At present, there are few reports on the properties of Al2O3·TiO2 coating and its application in solid parts. NiAl self-adhesive bottom layer and Al2O3·TiO2 ceramic surface layer were prepared on GH4169 test piece by using plasma spraying equipment. Then, the microstructure, microhardness, bonding strength and bending properties were tested. Based on the test results, the spray verification was carried out with a certain type of aeroengine solid parts. Results showed that the comprehensive performance of the Al2O3·TiO2 ceramic coating was good, When Al2O3·TiO2 ceramic coating was used in labyrinth sealing parts, it could effectively protect the labyrinth, preventing labyrinth from wear, and could improve the service performance of the parts and prolong its service life.