S-scheme Sb2WO6/g-C3N4 photocatalysts with enhanced visible-light-induced photocatalytic NO oxidation performance

Normal photocatalysts cannot effectively remove low-concentration NO because of the high recombination rate of the photogenerated carriers.To overcome this problem,S-scheme composites have been developed to fabricate photocatalysts.Herein,a novel S-scheme Sb2WO6/g-C3N4 nanocomposite was fabricated by an ultrasound-assisted method,which exhibited excellent performance for photocatalytic ppb-level NO removal.Compared with the pure constituents of the nanocomposite,the as-prepared 15%-Sb2WO6/g-C3N4 photocatalyst could remove more than 68%continuous-flowing NO(initial concentration:400 ppb)under visible-light irradiation in 30 min.The findings of the trapping experiments confirmed that•O2^–and h+were the important active species in the NO oxidation reaction.Meanwhile,the transient photocurrent response and PL spectroscopy analyses proved that the unique S-scheme structure of the samples could enhance the charge separation efficiency.In situ DRIFTS revealed that the photocatalytic reaction pathway of NO removal over the Sb2WO6/g-C3N4 nanocomposite occurred via an oxygen-induced route.The present work proposes a new concept for fabricating efficient photocatalysts for photocatalytic ppb-level NO oxidation and provides deeper insights into the mechanism of photocatalytic NO oxidation.

Global land-surface air temperature change based on the new CMA GLSAT data set

The China Meteorological Administration(CMA)has recently developed a new global monthly homogenized land-surface air temperature data set.Based on this data set,we reanalyzed the change in global annual mean land-surface air temperature(LSAT)during three time periods(1901–2014,1979–2014 and 1998–2014).The results show that the linear trends of global annual mean LSAT were 0.104°C/decade,0.247°C/decade and 0.098°C/decade for the three periods,respectively.The trends were statistically significant except for the period 1998–2014,the period that