Chao Teng

High-strength, flexible, and multifunctional characteristics are highly desirable for electromagnetic interference (EMI) shielding materials in the field of electric devices. In this work, inspired by natural nacre, we fabricated large-scale, layered MXene/amarid nanofiber (ANF) nanocomposite papers by blade-coating process plus sol–gel conversion step. The as-synthesized papers possess excellent mechanical performance, that is, exceptional tensile strength (198.80 ± 5.35 MPa), large strain (15.30 ± 1.01%), and good flexibility (folded into various models without fracture), which are ascribed to synergetic interactions of the interconnected three-dimensional network frame and hydrogen bonds between MXene and ANF. More importantly, the papers with extensive continuous conductive paths formed by MXene nanosheets present a high EMI shielding effectiveness of 13188.2 dB cm2 g–1 in the frequency range of 8.2–12.4 GHz. More interestingly, the papers show excellent Joule heating performance with a fast thermal response (<10 s) and a low driving voltage (≤4 V). As such, the large-scale MXene/ANF papers are considered as promising alternatives in a wide range of applications in electromagnetic shielding and thermal management.

A series of metal-free organic dyes bridged by anthracene-containing π-conjugations were designed and synthesized as new chromophores for the application of dye-sensitized solar cells (DSCs). Detailed investigations on the relationship between the dye structures, photophysical properties, electrochemical properties, and performances of DSCs are described. With the introduction of the anthracene moiety, together with a triple bond for the fine-tuning of molecular planar configurations and to broaden absorption spectra, the short-circuit photocurrent densities (Jsc) and open-circuit photovoltages (Voc) of DSCs were improved to a large extent. The improvement of Jsc is attributed to much broader absorption spectra of the dyes with the anthracene moiety. Electrochemical impedance spectroscopy (EIS) analysis reveals that the introduction of the anthracene moiety suppresses the charge recombination arising from electrons in TiO2 films with I3− ions in the electrolyte, thus improving Voc considerably. On the basis of optimized molecular structures and DSC test conditions, the dye TC501 shows a prominent solar energy conversion efficiency (η) up to 7.03% (Jsc = 12.96 mA·cm−2, VOC = 720 mV, ff = 0.753) under simulated AM 1.5 irradiation (100 mW·cm−2).

Dye-sensitized solar cells (DSCs) based on two novel carbazole dyes (TC301 and TC306) and a Br(-)/Br(3)(-) redox mediator in dried CH(3)CN solutions as electrolytes yielded a V(oc) of 1.156 V and a eta value of 3.68% and a V(oc) of 0.939 V and a eta value of 5.22% under simulated AM 1.5, respectively. The dyes TC301 and TC306 have more positive HOMO levels (1.59 and 1.38 V vs NHE) than the redox potential of Br(-)/Br(3)(-)-based electrolytes, which have sufficient driving force to regenerate dyes. Under similar conditions with an I(-)/I(3)(-) instead of a Br(-)/Br(3)(-) redox mediator, DSCs sensitized by the dyes TC301 and TC306 produced a V(oc) of 0.696 V and a eta value of 2.36% and a V(oc) of 0.621 V and a eta value of 4.10%, respectively.