Gas Sensors Based on Copper‐Containing Metal‐Organic Frameworks, Coordination Polymers, and Complexes

Abstract

In the last years, chemical research has allowed the obtainment of a large number of new sensing compounds useful in diverse interest areas related to health, environment, food, automotive, and steel industries, among others. Taking into account the interest and demand of sensors on a large scale and the urgent need to reduce the size of devices to nanometric scale, coordination compounds (CCs) ‐and more specifically those based on copper‐ have gained full acceptance. CCs present exciting characteristics such as (i) dynamic structures, (ii) ability to form an immense variety of porous structures, or (iii) easy nano processing. Besides, copper is abundant, and an essential ion in the human body with no high toxicity at reachable detectable concentrations. Just this one element copper allows us to obtain porous, non‐porous, optoelectronics, and/or magnetic‐sensitive compounds that can detect a highly varied range of gases in different devices at economical costs. Several studies show how the properties of this type of compounds can be improved depending on their synthesis conditions or by the technology used in the sensor fabrication.

Layered Double Oxides for Sensing Reducing Volatile Organic Compounds: The Effect of Local Charge Region Modulation

“…Figure 2 showed the representative FESEM images of CuCr‐, ZnCr‐ and ZnTi‐LDOs samples and their corresponding LDHs precursors. Note that the synthesis of 2D CuCr‐LDHs in Figure 2(a) was rarely explored before, for Cu atoms are generally enforced to lie in the energetically unfavorable position in the brucite‐type structure due to Jahn‐Teller effect [22–25] . In present work, the 2D CuCr‐LDHs were synthesized successfully by a soft template (SDS) assisted hydrothermal precipitation method, as shown in Figure 2(a).…”

“…Note that the synthesis of 2D CuCr-LDHs in Figure 2(a) was rarely explored before, for Cu atoms are generally enforced to lie in the energetically unfavorable position in the brucite-type structure due to Jahn-Teller effect. [22][23][24][25] In present work, the 2D CuCr-LDHs were synthesized successfully by a soft template (SDS) assisted hydrothermal precipitation method, as shown in Figure 2(a). Observe that the obtained CuCr-LDHs show morphology of well-defined 2D nanosheets with thickness of about 30-50 nm.…”

2D Cu(I)-I Coordination Polymer with Smart Optoelectronic Properties and Photocatalytic Activity as a Versatile Multifunctional Material

“…These characteristics are used to generate multifunctional materials that respond to multiple physical or chemical stimuli, producing a change in their properties. Accordingly, they can have interesting applications as sensors . Moreover, studies have been carried out on the electrical behavior of CPs both in bulk and in nanomaterials. , One of the main goals in this context has been to exploit these materials in electronic devices, with a high degree of functionality, absent in common semiconductors or metals. , …”

Multifunctional Platform Based on a Copper(I) Complex and NaYF4:Tm3+,Yb3+ Upconverting Nanoparticles Immobilized into a Polystyrene Matrix: Downshifting and Upconversion Oxygen Sensing

“…However, some complexes have voids in their crystal structure that allow permeation of oxygen and other gaseous molecules. Through these accessible channels, reactive molecules interact with the emitting site of the excited complex, leading to emission quenching. ,, When properly hosted in polymers , or mesoporous silica matrices , and upon exposure to O 2 , even complexes that do not exhibit such voids, as those based on tetranuclear copper­(I) clusters, exhibit rigidochromic and emission quenching effects, enabling their application in gas sensing. In a previous work, we have demonstrated that the sensitivities of these host–guest materials can exceed by 5 times the sensitivity of the copper­(I) complexes which exhibit structural voids …”