Surfactant effects on electrochemically durable lead halide perovskite electro-catalysts.

Electrochemically durable perovskite electrodes of nickel foam/TiO2/FA(Pb1-xGex)I3, passivated using various surfactants of tetra-n-alkyl ammonium halides (alkyl = ethyl, butyl, hexyl, or octyl; halide = I, I0.5Br0.5, Br, Br0.5Cl0.5, or Cl), were successfully applied as good electro-catalysts on the counter electrodes in dye-sensitized solar cells (DSSCs). The longer alkyl chain of a surfactant resulted in a higher water contact angle, but poorer film conductivity. Based on the optimal tetra-n-hexyl ammonium (THA) cation, shrinking the halide radius of THA from I to I0.5Br0.5 formed an appropriate amount of FAPbBr3 nano-crystals covering on the FA(Pb1-xGex)I3 grain surface. This phenomenon not only suppressed the perovskite decomposition under electrochemical measurements, but also created additional electro-catalytic active sites for triggering the iodide/triiodide redox reaction. Further shrinking the halide radius of THA from I0.5Br0.5 to Cl resulted in a severe self-aggregation of THACl, leading to an insufficient passivation and thereby poor electrochemical performance. In an ambient environment with a relative humidity higher than 75%, the optimal perovskite electrode of nickel foam/TiO2/FA(Pb1-xGex)I3-THAI0.5Br0.5 maintained the good crystallinity of α-FAPbI3 at least for 6 months, without obvious decomposition. Compared to the DSSC couple with a common counter electrode of nickel foam/Pt (8.74%), a better cell performance of 8.87% was achieved using the counter electrode of nickel foam/TiO2/FA(Pb1-xGex)I3-THAI0.5Br0.5, which was attributed to its good intrinsic electro-catalytic activity, large surface area, multiple active sites, and decent thermodynamic stability. Under room light illumination, higher cell efficiencies were obtained at 1 klux (21.5% for an office), 3 klux (22.9% for a shopping window), and 6 klux (22.3% for a lampshade). There is no doubt that air-stable perovskites have great potential in showing high performance for various electrochemical devices.

Factors affecting Taiwanese smokers' identification of smuggled cigarettes.

OBJECTIVES: To analyze whether the perception that smuggled cigarettes are a greater health risk than legal cigarettes affects Taiwanese smokers' intention to distinguish smuggled cigarettes from legal cigarettes. METHODS: The study used the Recursive Bivariate Probit Model to analyze data from a survey conducted in 2013 of 450 smokers of smuggled cigarettes. RESULTS: The study found that when smokers believe they are more likely to get lung cancer from consuming smuggled cigarettes than they are from consuming legal cigarettes, the probability of the intention to identify smuggled cigarettes increased by 42.46%. CONCLUSIONS: The government should strengthen educational policies and programs that teach consumers about the health risks of smoking in general and the even greater health risks of smoking smuggled cigarettes in particular.