Synthesis of reduced graphene oxide–TiO2 nanoparticle composite systems and its application in hydrogen production

Striving Toward Noble-Metal-Free Photocatalytic Water Splitting: The Hydrogenated-Graphene–TiO2 Prototype

“…Otherwise, Dubey at el. 27 observed that 2 wt% of RGO facilitated the fastest H 2 generation rate, 127.5 µmol cm -2 h -1 whereas slightly lower activities were obtained as increasing RGO amount to 5 and 10 wt%. Similarly, Gao et al 23 found that the optimal H 2 evolved amount, ca.…”

“…Considering several other GR/TiO 2 composites synthesized and reduced by different methods, [15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30] due to the higher work function, Φ GR = -4.42 eV (vs. vacuum) and Φ TiO2 = -4. 2 eV, 21,80 GR acts as the electron acceptor and conductor to capture and shuttle photoexcited electrons from the conduction band of TiO 2 , efficiently prolonging the lifetime and improving the mobility of electrons (whilst photogenerated holes are scavenged by the methanol sacrificial agent) and thus, facilitating H 2 production.…”

“…The origin of such properties is largely due to simultaneously enhanced adsorption capacity, extended light absorption, superior stability and excellent electron transport. [15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30] TiO 2 is the most widely used photocatalyst with a high propensity for generating pairs of electrons and holes upon photon absorption. 31,32 A noteworthy obstacle is that both the rapid recombination of these charge carriers within nanoseconds and the limited absorption in the near-UV region renders diminished either efficiency or activity of the photocatalytic reaction and partially limits its wide use in practical applications.…”

“…[15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30] GR sheets efficiently suppress the recombination of photoinduced electron-hole pairs, accelerate the transfer of electrons, enhance the surface-adsorbed quantity of target molecules via π-π and electrostatic interactions, as well as extend the absorption range to the visible light region by either narrowing the bap gap or introducing an additional gap. [15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30] Despite the fact that a cornucopia of scientific studies devoted to GR/TiO 2 composite materials has been reported, our fundamental understanding of these materials appears to have reached a plateau. Meanwhile, combining TiO 2 with fully hydrogenated graphene (known as 'graphane') or partially/half-hydrogenated graphene (as 'graphone') has not been achieved and remains at the fore front of photoelectrochemical research.…”

Fabrication of nanocomposites composed of silver cyanamide and titania for improved photocatalytic hydrogen generation

“…[3,4] Moreover, a good response to sunlight and high quantum conversion efficiency are also regarded as important factors in the design of photocatalysts. For example, various nanocomposites, such as TiO 2 /CdS, [8] TiO 2 /PdO, [9] TiO 2 /CuO, [10] TiO 2 /SnO x , [11] TiO 2 /WO 3 , [12] TiO 2 /graphene, [6,[13][14][15] TiO 2 /noble metal (Ag, Au, or Pt) , [16][17][18] TiO 2 -AgX [19,20] etc, have been reported with improved photocatalytic activity under visible light irradiation. [3][4][5] TiO 2 is a most widely investigated photocatalyst in the mineralization of organic pollutants as well as hydrogen generation because of its chemical stability, long-term thermodynamic stability, low cost, long-toxicity.…”