N,Cu-CD-Decorated Mesoporous WO3 for Enhanced Photocatalysis Under UV–Vis–NIR Light Irradiation

Research on the design of semiconductor photocatalysts with rapid electron transfer efficiencies and broad-spectrum responses for environmental remediation remains a pressing challenge. Herein, we described the fabrication of a novel broad-spectrum nitrogen and copper codoped carbon dots/mesoporous WO3 nanocomposite (N,Cu-CDs/m-WO3), which exhibited complete UV–vis–NIR spectrum response, light harvesting capabilities, rich oxygen vacancies, rapid electron-transfer ability, low electron–hole (e−/h+) pair recombination rate, and extensive specific surface area. After 2 h of photocatalytic reaction, it showed excellent photoactivities for the degradation of rhodamine B, methylene blue, tetracycline hydrochloride, oxytetracycline, ciprofloxacin, and bisphenol A. Moreover, we found that the conversion between Cu (II) and Cu (I) played a key role in accelerating electron transfer and inhibiting the recombination of e−/h+ pairs. This work provides an efficient strategy for the utilization of solar light and enhancing the charge-transfer capacity in the semiconductor photocatalysis field.

Bio-Inspired Soft Swim Bladders of Large Volume Change Using Dual Dielectric Elastomer Membranes

The buoyancy control mechanism is critical for undersea robots to achieve effective vertical motion. However, current buoyancy control mechanisms are associated with problems such as complex design, bulky structure, noisy operation, and slow response. Inspired by the swim bladder of natural fish, we develop an artificial swim bladder, using dual membranes of the dielectric elastomer, which exhibit interesting attributes, including fast response, light weight, silent operation, especially large volume change. Both the experiments and theoretical simulations are conducted to analyze the performance of this artificial swim bladder, and they quantitatively agree with each other. This artificial swim bladder of dual membranes is capable of large voltage-induced volume change, 112% larger than the conventional single-membrane design. Consequently, this soft actuator can generate a buoyancy force of 0.49 N. This artificial swim bladder demonstrates effective up-and-down motion in water, due to its large reversible volume change. Future work includes adding horizontal-motion and turning capabilities to the existing robotic structure, so that the soft robotic fish can achieve successful navigation in undersea environments.

Photoreception

“Photoreception” is the ninth chapter of the book Sensory Transduction and begins with general mechanisms of light detection, photopigment activation, and the variety of pathways of phototransduction using the scallop eye as an example. There is then a thorough treatment of the photoreceptors of arthropods, particularly those of Limulus and Drosophila. Following a description of photoreceptor anatomy, the chapter describes transduction in these arthropods including photoreceptor channels and the role of Ca2+ in the regulation of gain and turnoff. It then proceeds to vertebrate rods and cones, with individual treatment of the topics of transduction in vertebrate photoreceptors, the ion channels of rods and cones, the description and measurement of the photocurrent, pathways responsible for shutting down the light response, light adaptation, pigment renewal, and the recovery of sensitivity after bright light exposure. It concludes with transduction in intrinsically photosensitive retinal ganglion cells.