Enhanced Photocatalytic Oxygen Evolution by Crystal Cutting

Abstract

Uniformly cut In2O3 truncated octahedrons are fabricated on a large scale by a simple chemical vapor deposition (CVD) technique. This theoretical analysis predicts that the emergence of {100} facets on the In2O3 truncated octahedrons enhances oxygen evolution significantly in photocatalysis and experimental photoelectrochemical measurements are consistent.

Cubic In2O3 Microparticles for Efficient Photoelectrochemical Oxygen Evolution

“…Ω⋅cm which is larger than that of In 2 O 3 truncated octahedrons (0.58 Ω⋅cm) and octahedrons (0.35 Ω⋅cm) 5. In addition, the nearly identical absorption features in all the polyhedral samples indicate that the enhanced oxygen evolution reaction (OER) of the In 2 O 3 microcubes cannot be ascribed to improved solar light harvesting due to narrowing of the band gap caused by oxygen vacancies, as reported by previous investigations 19,20.…”

“…27,34 To demonstrate this effect, more investigation is performed and it is found that when the flow rate is reduced to 100 sccm (standard-state cubic centimeter per minute), only slightly truncated 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 To evaluate the PEC water splitting properties of the In 2 O 3 cubes, photoelectrocatalytic tests are conducted in a deaerated (purified with high purity N 2 (99.9995%)) three-electrode configuration ( Figure S12 in Supporting Information) employing an epoxy-sealed In 2 O 3 microcrystal sample as the working electrode with an exposed area of 0.8 cm 2 , Pt mesh as the counter electrode, Ag/AgCl (3 mol L -1 KCl-filled) as a reference electrode, and 1 M NaOH (pH = 13.6) solution as the electrolyte. Figure 5a and Figure 5 This demonstrates that the photocurrent in the process of PEC water splitting is proportional to the percentage of the exposed {001} facets among all the exposed facets. …”

“…5,15,[19][20][21][22] Unique to In 2 O 3 facets is that polar {001} facets have the capability to dissociate adsorbed H 2 O molecules into H + and OH − , whereas nonpolar {111} facets cannot do so. 5,15 This suggests that the photocatalytic activity can be enhanced appreciably by precise cutting of the specific crystal facets.…”

Up-scaling the synthesis of Cu2O submicron particles with controlled morphologies for solar H2 evolution from water

“…6). Moreover, the capability of {0 0 1} facets of the cubic particles to dissociate adsorbed water molecules can additionally enhance their PEC performance [38,39]. Further improvements of the electrode stability as well as shape and size effect of Cu 2 O particles on the solar H 2 evolution performance are being investigated.…”

Facet-controlled synthesis and facet-dependent photocatalytic properties of SnO2 micropolyhedrons

“…Among the various metal oxide materials, SnO 2 has attracted much attention especially in the fields of gas sensors [1], dye-based solar cells [2], lithium-ion batteries [3], supercapacitors [4], transparent conducting electrodes [5], catalyst support [6][7][8], and photodetector [9]. It has been shown that controlling the exposed facets during synthesis is an effective method to tailor the functionalities of various materials [6][7][8][9][10][11][12][13][14][15][16][17][18][19]. However, the surface-dependent properties of SnO 2 have not been studied as extensively, possibly due to the practical difficulty in obtaining SnO 2 structures with the desirable surface characteristics.…”