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A series of mesoporous nano-MgO-ZrO2 with various Mg:Zr atomic ratios were prepared via simple co-precipitation process without addition of a template. It was demonstrated by XRD, N2 adsorption-desorption and TEM that these samples still kept well mesoporous structure even after calcination at 600 °C. During the preparation process, divalent Mg2+ ions could be incorporated into tetragonal ZrO2 lattice to form a solid solution. More important, the surface basic density of these catalysts closely depended on their Mg content. Then, the resulting MgO-ZrO2 catalysts were used as basic catalysts for the dipropyl carbonate (DPC) synthesis via transesterification of n-propanol and dimethyl carbonate. The relationship between the basic property of solid base and their catalytic performance was clarified in detail. Among all the materials, the catalyst with Mg:Zr atomic ratio = 0.5 showed the best catalytic performance. Under the suitable reaction conditions, the yield of DPC could reach 98.5% with 100% selectivity. In addition, based on the reusability test and catalyst characterization, this catalyst exhibited extraordinary structure stability and it could be reused at least four times without obvious loss of reactivity.

TiO2 compact layer (c-TiO2) is generally applied for high-efficiencies perovskite solar cells (MPSCs), but it shows a relatively low electron mobility, which may restrict some performance of the MPSCs. Herein, we demonstrated SnO2 compact layer (c-SnO2), which prepared by spray pyrolysis using a solution of dibutyltin bisacetylacetonate in ethanol, could be an excellent alternative compact layer for efficient hole-conductor-free printable MPSCs. The best device with such a c-SnO2 has achieved an efficiency of 13.77%, which is very comparable to that obtained by the device based on c-TiO2. Furthermore, the device with c-SnO2 showed less pronounced hysteresis effect, probably because of the higher electron mobility of SnO2 and less charge accumulation at the interfaces. The simple preparation process and improved hysteretic behavior pave the way for industrialization of PSCs.