Oxygen Vacancy Defects Boosted High Performance p-Type Delafossite CuCrO₂ Gas Sensors

Abstract

p-type ternary oxides can be extensively explored as alternative sensing channels to binary oxides with diverse structural and compositional versatilities. Seeking a novel approach to magnify their sensitivities toward gas molecules, e.g., volatile organic compounds (VOCs), will definitely expand their applications in the frontier area of healthcare and air-quality monitoring. In this work, delafossite CuCrO (CCO) nanoparticles with different grain sizes have been utilized as p-type ternary oxide sensors. It was found that singly ionized oxygen vacancies (V) defects, compared with the grain size of CCO nanoparticles, play an important role in enhancing the charge exchange at the VOCs molecules/CCO interface. In addition to suppressing the hole concentration of the sensor channel, the unpaired electron trapped in V provides an active site for chemisorptions of environmental oxygen and VOCs molecules. The synergetic effect is responsible for the observed increase of sensitivity. Furthermore, the sensitive (V defect-rich) CCO sensor exhibits good reproducibility and stability under a moderate operation temperature (<325 °C). Our work highlights that V defects, created via either in situ synthesis or postannealing treatment, could be explored to rationally boost the performance of p-type ternary oxide sensors.

Interplay of Solvation and Size Effects Induced by the Counterions in Ionic Block Copolymers on the Basis of Hofmeister Series

“…The self-assembly of amphiphilic block copolymers (BCPs) in selective solvents is increasingly attracting the attention of researchers in the past decades due to their potential applications in biological drug delivery, [1][2][3][4] microreactor chemistry, [5,6] and in novel nanostructural templating. [7][8][9] In selective solvents, neutral BCPs can form various morphologies such as spheres, [10] cylinders, [11][12][13][14] vesicles, [15,16] and lamellae, [17][18][19] which can be regulated by many factors, such as block length, [20,21] solvent composition, [22][23][24] pH, [25,26] and inorganic For Hofmeister ion series, the order of anion follows the sequence:…”

Counterion‐Mediated Self‐Assembly of Ion‐Containing Block Copolymers on the Basis of the Hofmeister Series

“…Self-assembly process is of great importance in biological systems for the formation of well-defined and monodisperse objects on multiple length scales, [1][2][3][4][5][6][7][8] which is due to their potential applications in biological drug delivery, [7][8][9][10] microreactor chemistry, [11,12] and in novel nanostructural templating. [13][14][15] Specially, amphiphilic neutral block copolymers (BCPs) are of particular interest as they combine compositional diversity and high functionality with various assembly pathways to achieve well-controlled morphologies.…”

Glucose‐Responsive Insulin and Delivery Systems: Innovation and Translation

“…[48a] A second H 2 O 2 -responsive polymeric vesicle system self-assembled from a poly(phenylboronic acid pinacol ester)-containing triblock copolymer was also used for a smart insulin delivery patch design. [49] In addition, Xu et al integrated microneedles with insulin-loaded and H 2 O 2 -responsive mesoporous silica nanoparticles. [50] Wang et al upgraded the microneedle into a core-shell structure by loading GOx and insulin at the core of the device with a surrounding shell embedded with CAT that serves as an active filter to scavenge excessive H 2 O 2 to mitigate the risk of inflammation caused by H 2…”