Spray Pyrolysis as a Combinatorial Method for the Generation of Photocatalyst Libraries

Abstract

An inexpensive, combinatorial method to evaluate an array of metal oxide materials as photocatalysts for solar fuel production utilizing spray pyrolysis is presented. This new approach capitalizes on the inherent properties of spray pyrolysis. We take advantage of the natural lateral gradient produced in a spray cone to fashion four-metal-threeat-a-time compositional triangular patterns on conductive glass substrates from simple nitrate salt precursor solutions. Subsequent annealing produces thin-film electrodes that are readily screened for photochemical activity using a simple laser scanner system. The apparatus employed is constructed from readily available commercial components, making it accessible to a wide number of laboratories. Our method complements other combinatorial methods in that it provides a chemically different environment for the formation of materials that might produce different morphologies and metal oxidation states and it allows for easy evaluation of layered structures, as well single-phase materials, thereby expanding the number of unique materials tested as potential photocatalysts. As a proof of principle, the discovery and optimization of a new Na-doped CuBi 2 O 4 photocatalyst is described.

Combinatorial Screening of Cu–W Oxide-Based Photoanodes for Photoelectrochemical Water Splitting

“…Previous work has shown a wide range of preparation and characterization methods for the high-throughput testing of catalysts. ,,− Ludwig and Schuhmann and coworkers ,− prepared thin-film metal oxide libraries as gradient materials by reactive magnetron cosputtering and investigated their PEC performance using an automated optical scanning droplet cell (OSDC). Spray pyrolysis is less commonly used but equally suitable for the production of gradient materials . We focus here on wet chemical preparation for the libraries.…”

“…Spray pyrolysis is less commonly used but equally suitable for the production of gradient materials. 31 We focus here on wet chemical preparation for the libraries. Along those lines, McFarland and coworkers 32 demonstrated an automated electrochemical deposition device using multiplexed PEC cells for metal oxide libraries.…”

Building a Library for Catalysts Research Using High‐Throughput Approaches

“…Catalyst compositions can be tuned broadly by varying the deposition conditions. The conditions include changing the target material or introducing a series of combinatorial shadow masks in the physical deposition system, [58][59][60] changing the reaction precursor or gas composition in the chemical deposition system, [61] and controlling the deposition voltage, current, and electrolyte compositions in the electrodeposition system. Masked deposition is the most general method for depositing thin films with the desired composition by placing masks between the sputtering target and the substrate to isolate specific targets or substrates.…”

“…photocatalyst by spray pyrolysis, [59] the investigation of M-Mn-Co (M = Pt, Cr, Pd) and Pd-Mn-Ru systems as Li-air battery catalysts by magnetron sputtering, [58] and the exploration of ternary Pt-Cr-V, Pt-Co-Cr, and quaternary Pt-Co-Cr-V catalysts for methanol electro-oxidation by sputter deposition. [63] In addition, compositions gradients can be obtained, which shows a constant change for the different components ratio on the physical dimensions.…”

Accelerated screening of Cu–Ga–Fe oxide semiconductors by combinatorial spray deposition and high-throughput analysis

“…Among these, spray pyrolysis has several advantages like scalability, moderate operation temperatures, and a simple way of adding dopants. 8 Furthermore, it can be easily implemented as combinatorial deposition method for (1) thickness gradients by adjusting the covered area of multiple spray cycles [9][10][11][12][13][14][15] and (2) composition gradients a Energy Conversion and Hydrogen, Center for Energy, AIT Austrian Institute of by capitalizing the lateral spread of the spray cone and overlapping different precursor solutions consecutively 16 or simultanously. [17][18][19] Directly mixing multiple solutions during a laterally resolved coating process has already been reported.…”