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Conversion of CO 2 into valuable chemicals via electrochemical CO 2 reduction reaction (CO 2 RR) is a promising technology to alleviate the energy crisis and the greenhouse effect. Herein, low-cost wood biomass was applied as the carbon source to prepare nitrogen (N)-doped carbon electrocatalysts for the conversion of CO 2 to CO and further as the cathode material for Zn−CO 2 batteries. By virtue of N-doping and assistance of FeCl 3 , a cedar biomass-derived three-dimensional (3D) N-doped graphitized carbon with a high N-doping content (5.38%), an ultrahigh specific surface area (1673.6 m 2 g −1 ), rich nanopores, and sufficient active N sites was successfully obtained, which exhibited super CO 2 RR activity with a high faradaic efficiency of 91% at a low applied potential of 0.56 V (vs RHE) and a long-term stability for at least 20 h. Furthermore, a Zn−CO 2 battery with it as the cathode material delivered a stable open circuit voltage of 0.79 V, a peak power density of 0.51 mW cm −2 at 2.14 mA cm −2 , and a maximum faradaic efficiency to CO of 80.4% at 2.56 mA cm −2 , indicating that it could be applied in a practical process by using CO 2 to generate power with the production of CO. Density functional theory calculations revealed that pyridinic N could more effectively decrease the free energy barriers for CO 2 RR and boost the reaction. This work not only revealed a facile approach to convert waste biomass into N-doped-graphitization carbon as valuable CO 2 RR electrocatalysts but also provided a new strategy to achieve "carbon solving carbon's problem".

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This study is concerned with the level of antibiotic resistance of extended-spectrum beta-lactamase (ESBL)-producing Klebsiella pneumoniae, isolated in Shantou, China, and its mechanism. Seventy-four non-repetitive clinical isolates of K. pneumoniae producing ESBLs were isolated over a period of 2 years. Antibiotic susceptibility, carried out by Epsilometer test, showed that most of the isolates were multiresistant. Polymerase chain reaction showed that, among the several types of beta-lactamases, SHV was the most prevalent, TEM was the second most prevalent, and CTX-M was the least prevalent. Sixty-nine isolates were positive for integrase gene IntI1, but no IntI2 or IntI3 genes were found. The variable region of class 1 integrons were amplified and further identified by sequencing. Thirteen different gene cassettes and 11 different cassette combinations were detected. Dfr and aadA cassettes were predominant and cassette combinations dfrA12, orfF and aadA2 were most frequently found. No gene cassettes encoding ESBLs were found. Integrons were prevalent and played an important role in multidrug resistance in ESBL-producing K. pneumoniae.