5Design and engineering of low-cost and high-efficiency electrocatalysts for hydrogen evolution reaction (HER) has attracted increasing interest in renewable energy research. Herein, MoS 2 nanosheets-coated CoS 2 nanowire arrays supported on carbon cloth (MoS 2 /CoS 2 /CC) were prepared by a two-step procedure that entailed hydrothermal growth of Co(OH) 2 nanowire arrays on carbon cloth, followed by reaction with (NH 4 ) 2 MoS 4 to grow an overlayer of MoS 2 nanosheets. Electrochemical studies showed that the obtained 10 3D electrode exhibited excellent HER activity with an overpotential of −87 mV at 10 mA cm −2 , a small Tafel slope of 73.4 mV dec −1 and prominent electrochemical durability. The results presented herein may offer a new methodology for the design and engineering of effective multilevel structured catalysts for HER based on earth-abundant components.

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N-doped carbon-coated cobalt nanorod arrays on a Ti mesh exhibited efficient HER performance with an overpotential of −56 mV, a Tafel slope of 78.2 mV dec−1 and robust stability.

Atmospheric benzene, toluene, ethylbenzene, and xylenes (BTEX) can lead to multiple health injuries. However, what remains uncertain is the effect of long-term exposure to low levels of BTEX. Thus, we determined the BTEX levels in the air from the refueling and office areas in gas stations. Then we collected workers’ (200 refueling vs. 52 office workers) peripheral blood samples to analyze the serum total-superoxide dismutase (T-SOD), glutathione (GSH), malondialdehyde (MDA), and 8-hydroxydeoxyguanosine (8-OHdG) levels. DNA damage was analyzed by the comet assay and micronucleus test in buccal epithelial cells. We found that the levels of BTEX in refueling areas were significantly higher than those in office areas (p < 0.001). The serum T-SOD and GSH of refueling workers were significantly lower than those in office workers (p < 0.001). By contrast, the serum MDA and 8-OHdG of refueling workers were significantly higher than those of office workers (p < 0.001, MDA; p = 0.025, 8-OHdG). Furthermore, tail and Olive tail moments in refueling workers were longer (p = 0.004, tail moment; p = 0.001, Olive tail moment), and the micronucleus rate was higher (p < 0.001) than those in office workers. Taken together, long-term exposure to low levels of BTEX may reduce the antioxidant ability and increase the risk of DNA damage in refueling workers of gas stations.