# The Application of Nano Titanium Dioxide for Hydrogen Production and Storage Enhancement
## 2 Titanium Dioxide
### Exploiting the TiO\({}_{2}\) Properties for Hydrogen Storage
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multicolumn{1}{c}{**Photocatalyst**} & \multicolumn{1}{c}{**Crystalline Phases of TiO\({}_{2}\)**} & \multicolumn{1}{c}{**Loading**} & \multicolumn{1}{c}{**Irradiation**} & \multicolumn{1}{c}{**Sacrificial Reagents**} & \multicolumn{1}{c}{**H\({}_{2}\) Production**} & \multicolumn{1}{c}{**Ref.**} \\ \hline Cu\({}_{2}\)O/TiO\({}_{2}\)/Bi\({}_{2}\)O\({}_{3}\) & anatase & 2 wt\% of Cu & solar light & glycerol & 6727 \(\mu\)mol h\({}^{-1}\) & [1] \\ \hline ZnTCPP-MoS\({}_{2}\)/TiO\({}_{2}\) & anatase/rutile & 1.00 wt\% of MoS\({}_{2}\) & visible light & TEOA & 10.2 \(\mu\)mol h\({}^{-1}\) & [10] \\ \hline Cu/TiO\({}_{2}\) & anatase/rutile & 2 wt\% of Cu & visible light & methanol & 220 \(\mu\)mol h\({}^{-1}\) g\({}^{-1}\) & [11] \\ \hline Co/TiO\({}_{2}\) & anatase/rutile & 1 wt\% of Co & solar light & glycerol & 11,021 \(\mu\)mol h\({}^{-1}\) g\({}^{-1}\) & [36] \\ \hline CuZn-TiO\({}_{2}\) & anatase & 0.5 wt\% of Cu & solar light & glycerol & 14,521 \(\mu\)mol h\({}^{-1}\) g\({}^{-1}\) & [38] \\ \hline Cu-Ni/TiO\({}_{2}\) & anatase/rutile & 2 mol\% of Cu & 5 mol\% of Ni\({}^{*}\) & solar light & methanol & 35.4 mmol h\({}^{-1}\) g\({}^{-1}\) & [39] \\ \hline Fe/TiO\({}_{2}\) & anatase & 0.5 wt\% of Fe\({}^{2*}\) & solar light & - & 270 \(\mu\)mol h\({}^{-1}\) & [40] \\ \hline ZrO\({}_{2}\)-TiO\({}_{2}\)/rGO & anatase & 1.0 wt\% of ZrO\({}_{2}\) & solar light & glycerol & 7773 \(\mu\)mol h\({}^{-1}\) g\({}^{-1}\) & [41] \\ \hline CuO/TiO\({}_{2}\) & anatase/rutile & 1.5 wt\% of Cu & solar light & glycerol & 99,823 \(\mu\)mol h\({}^{-1}\) g\({}^{-1}\) & [42] \\ \hline Ni(OH)\({}_{2}\)-Cu\({}_{x}\)O-TiO\({}_{2}\) & anatase & 1.0 wt\% of Ni(OH)\({}_{2}\) & solar light & glycerol & 7679 \(\mu\)mol h\({}^{-1}\) g\({}^{-1}\) & [43] \\ \hline CdS/TiO\({}_{2}\) & anatase & CdS:TiO\({}_{2}\) molar ratio of 1 & visible light & lactic acid & 76.55 \(\mu\)mol h\({}^{-1}\) & [44] \\ \hline CdS/WO\({}_{3}\)/TiO\({}_{2}\) & anatase & molar ratio 8\%:100 & visible light & Na\({}_{2}\)S and Na\({}_{2}\)SO\({}_{3}\) & 2106 \(\mu\)mol h\({}^{-1}\) g\({}^{-1}\) & [45] \\ WO\({}_{3}\)/TiO\({}_{2}\) & anatase & - & visible light & Na\({}_{2}\)S and Na\({}_{2}\)SO\({}_{3}\) & 981 \(\mu\)mol h\({}^{-1}\) g\({}^{-1}\) & [46] \\ \hline CdS/TiO\({}_{2}\)(B) & TiO\({}_{2}\)(B) & 5\% of CdS & visible light & Na\({}_{2}\)S and Na\({}_{2}\)SO\({}_{3}\) & 1577 \(\mu\)mol h\({}^{-1}\) g\({}^{-1}\) & [47] \\ \hline CdS/TiO\({}_{2}\) & anatase & - & visible light & Na\({}_{2}\)S and Na\({}_{2}\)SO\({}_{3}\) & 1.89 \(\mu\)mol h\({}^{-1}\) cm\({}^{-2}\) & [47] \\ \hline CuInS\({}_{2}\)/TiO\({}_{2}\)/MoS\({}_{2}\) & anatase & 0.5 wt\% of MoS\({}_{2}\) & visible light & Na\({}_{2}\)S and Na\({}_{2}\)SO\({}_{3}\) & 1034 \(\mu\)mol h\({}^{-1}\) g\({}^{-1}\) & [49] \\ \hline MoS\({}_{2}\)/TiO\({}_{2}\) & anatase & - & visible light & TEOA & 16.7 mmol h\({}^{-1}\) g\({}^{-1}\) & [50] \\ \hline Flower-like MoS\({}_{2}\)@TiO\({}_{2}\) and fluorescein & anatase & 14.6 wt\% of MoS\({}_{2}\) & visible light & TEOA & 10,046 \(\mu\)mol h\({}^{-1}\) g\({}^{-1}\) & [51] \\ \hline MoS\({}_{2}\)-CdS-TiO\({}_{2}\) & \multicolumn{1}{c}{3\% of MoS\({}_{2}\) and 10\% of CdS molar ratio to TiO\({}_{2}\)} & visible light & Na\({}_{2}\)S and Na\({}_{2}\)SO\({}_{3}\) & 4146 \(\mu\)mol h\({}^{-1}\) g\({}^{-1}\) & [52] \\ CdS-TiO\({}_{2}\) & \multicolumn{1}{c}{-} & \multicolumn{1}{c}{-} & \multicolumn{1}{c}{1360 \(\mu\)mol h\({}^{-1}\) g\({}^{-1}\)} & [53] \\ \hline MoS\({}_{2}\)/CdS-TiO\({}_{2}\) & \multicolumn{1}{c}{-} & \multicolumn{1}{c}{1 wt\% of MoS\({}_{2}\)} & visible light & lactic acid & 280.0 \(\mu\)mol h\({}^{-1}\) & [53] \\ \hline \hline \end{tabular}
\end{table} 
Table 1: TiO\({}_{2}\)-based photocatalysts modified with non-noble metals, metallic oxides, CdS, and MoS\({}_{2}\) for H\({}_{2}\) production under visible and solar light. in comparison to using Co or TiO\({}_{2}\) separately.