Activated‐Carbon‐Templated Crystalline Tantalates for Photocatalytic Water Splitting

Abstract

Herein, we report a facile nanocasting route for the preparation of crystalline mesoporous Ta₂O₅ and NaTaO₃ with a high surface area using activated carbon as the structure-directing hard template. The crystalline particles of Ta₂O₅ and NaTaO₃ have mean sizes of 6 and 9 nm, constructing mesoporous networks with surface areas of 91 and 75 m² g⁻¹, respectively. The photocatalytic performances of the tantalum-based replicas were investigated for the water splitting reaction by using methanol as sacrificial agent and better photocatalytic performances were observed in comparison with bulk and amorphous counterparts. Loading the templated Ta₂O₅ and NaTaO₃ with 1 wt % NiO_x boosted their photocatalytic activity. The most-active sample, NaTaO₃/NiO_x, was also tested for overall water splitting and it produced hydrogen and oxygen in stoichiometric ratios at rates of 129 and 66 μmol h⁻¹, respectively

Reactor Design and Kinetic Study on Adsorption/Desorption of CO and Cl2 for Industrial Phosgene Synthesis

“…Besides screening of some commercial carbon‐based materials, the synthesis of new carbonaceous catalysts is also planned, in which diverse synthetic strategies are used, e.g., (1) hard and soft templating method for well‐ordered carbonaceous materials , where our group has already experience with , (2) utilization of food waste as carbon source, i.e., spent tea leaves, coffee, etc. , , (3) mechanical shock via grinding and ball milling , , (4) activation with acids and bases, including phosphoric acid, KOH, K 2 CO 3 , as well as steam , and (5) hetero‐element doping by hydrothermal treatment or heat treatment under NH 3 (g) and H 2 S (g) atmosphere , .…”

Synthesis of Nb2O5 and Ta2O5 nanopowders by means of an endo-templating method

“…Compared to similar hard-templated methods, mentioned in the literature, our method is very competitive since values of specific surface areas of 10 to 51 m 2 /g and 90 m 2 /g coupled to pore volumes of 0.05 to 0.20 cm 3 /g and 0.32 cm 3 /g were obtained for crystallized Nb 2 O 5 and Ta 2 O 5 samples, respectively, synthesized from SBA-15, FDU-1 mesoporous silica matrices [28] and activated carbon [27]. Moreover, our process exhibit some advantages compared to the previously quoted methods as higher yields in term of nanostructured powder and also that the tricalcium phosphate template is cheaper than some of the suggested templates in particular the mesoporous silica materials.…”

“…Concerning the hard-templated route, less developed than the previous one for the current case, the synthesis of niobium (V) and tantalum (V) oxide ceramics may be synthesized by using (i) threedimensionally (ordered or not) macroporous architectures made of self-assembly of polystyrene beads [23][24][25][26], (ii) activated carbon [27] and (iii) ordered mesoporous silica materials such as SBA-15 and FDU-1 [28]. From this hard-template approach, the pore walls of the as-prepared Nb 2 O 5 and Ta 2 O 5 materials are well-crystallized since higher temperatures may be reached during the process without risking of losing the nanodimensions and the porous character of the materials.…”

Otto Roelen Medal: P. Strasser / Jochen Block Prize: H. Tüysüz / Leo Hendrik Baekeland Award: S. E. Skrabalak / Gustavus John Esselen Award: T. M. Swager

“…Tüysüz is interested in the development of well‐defined nanostructured materials, with particular focus on applications such as photo‐ and electrochemical water splitting, perovskite solar cells, biomass conversion, and plasmonic catalysis. He has reported in Angewandte Chemie on the synthesis of organometal halide perovskite inverse opals, and in ChemNanoMat on crystalline tantalates for photocatalytic water splitting …”