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The rational fabrication of Pt‐free catalysts for driving the development of practical applications in alkaline water electrolysis and fuel cells is promising but challenging. Herein, a promising approach is outlined for the rational design of multimetallic catalysts comprising multiple active sites including Pd nanoclusters and Ru single atoms anchored at the defective sites of Ni(OH)2 to simultaneously enhance hydrogen evolution reactions (HER) and ethanol oxidation reactions (EOR). Remarkably, Pd12Ru3/Ni(OH)2/C exhibits a remarkably reduced HER overpotential (16.1 mV@10 mA cm−2 with a Tafel slope of 21.8 mV dec−1) as compared to commercial 20 wt.% Pt/C (26.0 mV@10 mA cm−2, 32.5 mV dec−1). More importantly, Pd12Ru3/Ni(OH)2/C possesses a self‐optimized overpotential to 12.5 mV@10 mA cm−2 after 20 000 cycles stability test while a significantly decreased performance for commercial 20wt.% Pt/C (64.5 mV@10 mA cm−2 after 5000 cycles). The mass activity of Pd12Ru3/Ni(OH)2/C for the EOR is up to 3.724 A mgPdRu−1, ≈20 times higher than that of commercial Pd/C. Electrochemical in situ Fourier transform infrared measurements confirm the enhanced CO2 selectivity of Pd12Ru3/Ni(OH)2/C while synergistic and electronic effects of adjacent Ru, Pd, and OHad adsorption on Ni(OH)2 at low potential play a key role during EOR. [ABSTRACT FROM AUTHOR]

Carbon nanotube (CNT)–polymer composite films are key elements in widespread photonic and optoelectronic applications. One particular successful application is to produce ultrashort optical pulses in the laser cavity. Nevertheless, such composite film may suffer from severe humidity/water degradation, from which the laser may even stop generating regular pulses. Here, surfactant‐free CNT–styrene methyl‐methacrylate polymer composite film is fabricated. Based on such film‐type saturable absorber, a self‐starting passively mode‐locked erbium‐doped fiber laser with the capability of generating ≈1 ps pulses is demonstrated. From the perspective of experimental measurements and numerical simulations, the effectiveness of a saturable absorber in generating ultrashort pulses is confirmed. The operating composite film can survive under fully immersed water condition for 30 days. More importantly, after the non‐operating composite film has been fully soaked in the water tank for 2 days, it can still mode‐lock the laser as it is in dry air condition, confirming the humidity resistance capability. In addition, it is experimentally found that the mechanical packaging of the composite film has an impact on the survival time of composite film under water immersion. [ABSTRACT FROM AUTHOR]