Bio-Templating: An Emerging Synthetic Technique for Catalysts. A Review

Abstract

In the last few years, researchers have focused their attention on the synthesis of new catalyst structures based on or inspired by nature. Biotemplating involves the transfer of biological structures to inorganic materials through artificial mineralization processes. This approach offers the main advantage of allowing morphological control of the product, as a template with the desired morphology can be pre-determined, as long as it is found in nature. This way, natural evolution through millions of years can provide us with new synthetic pathways to develop some novel functional materials with advantageous properties, such as sophistication, miniaturization, hybridization, hierarchical organization, resistance, and adaptability to the required need. The field of application of these materials is very wide, covering nanomedicine, energy capture and storage, sensors, biocompatible materials, adsorbents, and catalysis. In the latter case, bio-inspired materials can be applied as catalysts requiring different types of active sites (i.e., redox, acidic, basic sites, or a combination of them) to a wide range of processes, including conventional thermal catalysis, photocatalysis, or electrocatalysis, among others. This review aims to cover current experimental studies in the field of biotemplating materials synthesis and their characterization, focusing on their application in heterogeneous catalysis.

Carbon-Coated TiO2 Nanoparticles for Noble-Metal-Free Photocatalytic H2 Production from H2O

“…4 As a reference cocatalyst, 7 Pt 0 -nanoparticles deposited on TiO 2 typically play a double role: (i) formation of a strong Schottky junction, which promotes storage of electrons from TiO 2 on Pt 0 , thanks to its work function (φ Pt = 5.65 eV vs φ TiO2 = 4.20 eV) 8 and (ii) Pt 0 can act as efficient σ-donor to H + , promoting H 2 evolution. 9 Further improvement can be achieved by so-called Z-scheme heterostructures 10 where Pt-TiO 2 is coupled with a second semiconductor. Pertinent examples include Pt/TiO 2 /gCN 10 and Pt/TiO 2 /NiO, 11 which showed improved H 2 generation.…”

“…9 Further improvement can be achieved by so-called Z-scheme heterostructures 10 where Pt-TiO 2 is coupled with a second semiconductor. Pertinent examples include Pt/TiO 2 /gCN 10 and Pt/TiO 2 /NiO, 11 which showed improved H 2 generation.…”

Investigating the Effect of Reflectance Tuning on Photocatalytic Dye Degradation with Biotemplated ZnO Photonic Nanoarchitectures Based on Morpho Butterfly Wings

“…With this technique, novel functional materials can be fabricated that combine the complex hierarchy of biological structures with the advantages of artificial materials [5]. These new inorganic functional materials are produced by incorporating the desired compounds into the templates created by nature, optionally followed by mineralization processes that may remove the templates through degradation [6]. It is especially exciting if photonic-crystal-type nanoarchitectures form the basis of the biological templates [7][8][9].…”

Microspherical Titanium-Phosphorus Double Oxide: Hierarchical Structure Development for Sensing Applications

“…Numerous utilizations of hierarchical structures facilitated the widespread development of their formation methods. A major avenue in this area of research is top-down methods based on natural templates [ 6 , 7 ], such as wood [ 8 ], leaves and diatoms [ 9 ]. In the bottom-up methods, molecular templates, such as surfactants [ 10 ], biopolymers [ 11 ] and peptides [ 12 ] are a commonly used group of structure formation means in the synthesis of sophisticated structures, but their utilization is problematic due to their high cost and low stability.…”