**Author details**

**Figure 36.** (a) TEM and (b) HRTEM images of sample AGT. (c) STEM model of Ag/rGO/TiO2.

Elemental mapping of (d) Ag and (e) Ti in the same area in (c). (f)Photocatalytic degradation of Rh B

under simulated sunlight irradiation over P25, Ag/rGO/TiO2 composites with different AgNO3

contents. (g) Comparison of the photocatalytic activity of rGO, P25 and Ag/rGO/TiO2 composites with

different AgNO3 contents for the photocatalytic H2 production under simulated sunlight irradiation[367].

Next, we have replaced the Ag with MoS2 quantum dots (QDs) and demonstrated a simple and an

efficient onepot approach to prepare MoS2 quantum dotsgrapheneTiO2 (MGT) composites using a

solvothermal method under obtained atmospheric pressures and at low temperatures (Fig. 37)[368]. The

**(e)** 

**Figure 37.** TEM and HRTEM images of the sample (a), (b) MGT4 and (c), (d)MoS2graphene. (e)

**Figure 37.** TEM and HRTEM images of the sample (a), (b) MGT−4 and (c), (d)MoS2−graphene. (e) Proposed mechanism for the photodegradation of RhB by MGT under simulated sunlight irradiation (f) Photocatalytic degradation and (g) photocatalytic degradation reaction of RhB under simulated sunlight irradiation over P25, MGT composites with dif‐

Proposed mechanism for the photodegradation of RhB by MGT under simulated sunlight irradiation (f)

Photocatalytic degradation and (g) photocatalytic degradation reaction of RhB under simulated sunlight

irradiation over P25, MGT composites with different MoS2 contents[368].

interaction between functional groups on GO sheets and Mo precursors in a suitable solvent

environment. In addition, it shows significantly increased photodegradation performance even without

Photocatalysis appears to be a promising avenue to solve environmental and energy issues in the future. Although the photocatalytic processes involve a complicated sequence of multiple synergistic or competing steps, the efficient utilization of solar energy (especial visible-light energy) and improvement in separation and transportation of charge carriers are the main challenges and current trend to design highly effective photocatalysts. Finally, we conclude that this chapter, after discussing with various materials and its composites for photocatalytic process, may be useful for further applications in the area of energy and environment. In summary, we have discussed the general strategies and recent progress in photocatalysis for developing highly efficient and stable photocatalysts, including: (1) Titania (TiO2), iron oxides (α-Fe2O3); (2) ternary oxide photocatalytic matericals, such as Bi systems photocatalytic materials and (3) semiconducting materials and its composites. The achieved progress in photocatalysis indicates a promising route to enhance the photocatalytic efficiencies of

a noble‐metal cocatalyst, which is due to the increased charge separation, visible‐light absorbance,

specific surface area and reaction sites upon the introduction of MoS2 QDs. Besides, the enhancement

mainly came from holes left in the TiO2 crystals rather than electrons transferring to reduced graphene

Photocatalysis appears to be a promising avenue to solve environmental and energy issues in the

To date, in addition to different kinds of semiconductor materials and its composites significant advances have been reported to improve the photocatalytic efficiencies that range from environmental remediation to clean−energy harvesting by enhancing the utilization of sunlight or improving the separation/transportation of the electron−hole pairs some examples

future. Although the photocatalytic processes involve a complicated sequence of multiple synergistic or

competing steps, the efficient utilization of solar energy (especial visible‐light energy) and improvement

in separation and transportation of charge carriers are the main challenges and current trend to design

highly effective photocatalysts. Finally, we conclude that this chapter, after discussing with various

materials and its composites for photocatalytic process, may be useful for further applications in the area

of energy and environment. In summary, we have discussed the general strategies and recent progress

in photocatalysis for developing highly efficient and stable photocatalysts, including: (1) Titania (TiO2),

shape of MoS2 obtained using this method is quantum dot instead of a layered sheet because of the

**(f) (g)**

212 Advanced Catalytic Materials - Photocatalysis and Other Current Trends

oxide (RGO).

**Summary and outlook**

ferent MoS2 contents [368].

**5. Summary and outlook**

photocatalytic semiconductors.

Le Li and Minqiang Wang\*

\*Address all correspondence to: mqwang@mail.xjtu.edu.cn

Electronic Materials Research Laboratory (EMRL), Key Laboratory of Education Ministry, International Center for Dielectric Research, Xi'an Jiaotong University, Xi'an, China
