Simply Coupling TiO₂ Nanospheres with Cu₂O Particles to Boost the Photocatalytic Hydrogen Evolution through p–n Heterojunction‐Induced Charge Transfer

Abstract

utilizing semiconductors as photocatalysts to convert solar energy into hydrogen energy reasonably becomes a viable, sustainable, and promising approach to generate hydrogen. [3] Among various photocatalysts, TiO 2 is an ideal n-type model of semiconductor photocatalyst and has always attracted increasing attention because it is cheap, stable, nontoxic, and environmentally friendly. [4] Although TiO 2 has good chemical stability and proper energy band level for water splitting, it owns a poor response for the visible light, and the photoinduced charge carriers have a trend of fast recombination during the reactions, which restricts its application in water splitting. [5] Over the past decades, many efforts have been paid on developing effective approaches such as crystal phase engineering, [6] cocatalyst modification, [7] and heterojunction construction [8] to ameliorating the aforementioned issues.Cuprous oxide (Cu 2 O), a p-type semiconductor with a direct bandgap of 2-2.2 eV, [9] is abundant in Earth and relatively simple to be synthesized, which reflects its great potential in photocatalysis application. [10] In particular, Cu 2 O could be served as an excellent candidate for coupling with n-type semiconductor to improve the photoelectric properties and upgrade the catalytic performance in photocatalysis applications ultimately. In recent

A facile way to synthesize noble metal free TiO2 based catalysts for glycerol photoreforming

“…Commercial P25 displays a band-gap values of 3.14 eV typical of the anatase-rutile mixture; the deposition of Pt does not modify the value but increases the absorption in the visible region (Figure 3). The band gap of commercial Cu2O is 1.99 eV, in accordance with the literature [25,34] whilst it was not possible to measure the value for CuO due to the high absorption over all the measured wavelengths range (Figure 3). The composites samples containing Cu2O present two absorption edges corresponding to the two oxides (at ca.…”

“…The use of Cu2O is particular interesting because it presents different advantages as low toxicity, low cost, low band gap (2.0-2.2 eV) and conduction band energy suitable for H + reduction [23]. The major drawback of this oxide is the instability of Cu + in the presence of humidity and light; one possible approach to improve its stability is to slow down the charge recombination by coupling it with other semiconductors [23][24][25].…”

Durable CuxO/mesoporous TiO2 photocatalyst for stable and efficient hydrogen evolution

“…2f and g reveal lattice spacing of 0.35 nm, attributed to the anatase TiO 2 (101) plane, 17 and lattice spacing of 0.25 nm, corresponding to either the (002) plane of CuO 27 or the (111) plane of Cu 2 O. 28 Fig. 2h shows a typical type IV N 2 sorption isotherm with hysteresis that indicates a mesoporous structure with a pore size distribution centred at 17 nm (see inset).…”

Photocatalytic Carbon Dioxide Conversion by Structurally and Materially Modified Titanium Dioxide Nanostructures

“…Further, the junction can be designed in such a way that the light absorption range of one semiconductor can be extended by choosing the other semiconductor with a smaller band gap. Therefore, two fundamental challenges, light absorption and charge carrier separation, in TiO 2 -based photocatalysts n photocatalysis- can be tackled by creating p-n junction with materials that have suitable band gaps and intimate energy band structure [ 111 ].…”