The quality of heterojunctions at the quantum dot (QD)‐TiO2 nanotube (TNT) interface has important implications on the efficiencies of photoelectrochemical solar cells. Here, it is shown that electrophoretic deposition of pre‐synthesized thioacid‐capped CdTe QDs results in relatively poor charge transfer across the heterojunctions. This is likely due to the intermediate layer of bifunctional linkers (S‐R‐COOH) in between the QDs and TNT. On the other hand, CdTe QD‐sensitized TNT prepared by in situ deposition in aqueous medium provides direct QD‐TNT contact, and hence more favorable heterojunction for charge transfer. This is exemplified not only by the drastic improvement in photocurrent efficiencies, but also provides clear difference on the size‐dependent electron injection efficiencies from the CdTe QDs of different sizes. By extending the system further to CdSe QDs, drastic enhancement is found when carrying out the in situ deposition in an organic medium. The results are discussed in terms of the nature of deposition and the corresponding charge transport characteristics. More importantly, the work reflects the intricacy of the effects of QD size and the quality of the heterojunctions on the overall photoconversion efficiencies.

A highly dispersed and active PdNi alloy supported on reduced graphene oxide (rGO) was successfully prepared for formic acid electro-oxidation under acidic conditions. The material was prepared by a simultaneous reduction method using NaBH 4 as the reductant, followed by annealing in H 2 at 500 C.Different characterization methods verified that H 2 annealing at an appropriate temperature had a significant influence on both physiochemical composition and electrocatalytic performance of the synthesized catalysts. H 2 annealing at 500 C facilitated formation of a PdNi alloy without agglomeration of the nano-sized metallic catalyst, while without H 2 treatment Ni was found predominantly in the form of Ni(OH) 2 . Cyclic voltammetry and chromoamperometric testing demonstrated that, when compared to the sample without H 2 treatment, PdNi/rGO after H 2 annealing exhibited better catalytic activity and stability towards formic acid electro-oxidation. The enhanced performance can be explained by the modification of the electronic structure of Pd by Ni after alloy formation and the large specific surface area and excellent electron conductivity of the rGO support.

Ag-Ag2S hybrid nanoparticles were deposited onto Anatase anodic TiO2 nanotubular arrays via a one-step in situ hydrothermal method. Characterization was carried out using FE-SEM, HRTEM, XRD, XPS and UV-vis DRS. The fabricated nano-composites exhibit high visible light-sensitivity and photocurrent output as photoanodes in photoelectrochemical applications. The outstanding performance of the final composite is attributed to the surface plasmonic resonance effect of Ag, which is further enhanced by an Ag2S outer-layer.

Increasing utilization of solar energy is an effective strategy to tackle our energy and energy-related environmental issues. Both solar photocatalysis (PC) and solar photovoltaics (PV) have high potential to develop technologies of many practical applications. Substantial research efforts are devoted to enhancing visible light activation of the photoelectrocatalytic reactions by various modifications of nanostructured semiconductors. This review paper emphasizes the recent advancement in material modifications by means of the promising localized surface plasmonic resonance (LSPR) mechanisms. The principles of LSPR and its effects on the photonic efficiency of PV and PC are discussed here. Many research findings reveal the promise of Au and Ag plasmonic nanoparticles (NPs). Continual investigation for increasing the stability of the plasmonic NPs will be fruitful.

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