All the reagents were analytical grade (AR) and used without further purification. They were purchased from Sigma-Aldrich Corp and Beijing Chemical Reagents Co. Deionized water was decarbonized by boiling and bubbling N₂ before employing all synthesis steps.

Layered double hydroxides were synthesized by a co-precipitation method. The synthetic method was described as follows: an aqueous, (A) solution (200 mL) containing 3.60 g, NaOH (0.09 mol) and (B) solution (200 mL) containing 9.55 g Zn(NO₃)₂·6H₂O (0.032 mol) or 8.205 g Mg(NO₃)₂·6H₂O (0.032 mol) or 9.305 g, Ni(NO₃)₂·3H₂O (0.032 mol) of salts. Then, both solutions were added dropwise together into Na₂CO₃ (100 mL) in a flask with vigorous stirring until the final pH of (7) ± 0.2. Then, the heat of the reaction was raised to 65˚C for 18 h and then washed with hot deionized water three times to bring the pH down to 7. Finally, it was dried in an oven at 65˚C for 18 h, then ground, giving the product M²⁺/Ti⁴⁺ Al³⁺-CO₃-LDHs.

Thermogravimetric Analysis (TGA) from Nietzsche (STA 449F3) was used, which was equipped with a crucible volume = 0.05 mg with a lid. The sample was heated from 20˚C to 700˚C with 5/min in a streaming nitrogen. Powder X-ray diffraction (XRD) patterns were registered on a Riga ku RINT 2000 powder diffractometer, using (λ = 1.54Å) at 40 kV and 178 mA and a scanning rate of 10˚/min in the range of 3˚ - 70˚. (UV) The transitions that result in the absorption of electromagnetic radiation and, also, where the ultraviolet (UV) for the region scanned is normally from 200 to 900 nm of the spectrum are transitions between electronic energy levels means for a Shimadzu UV-3600 spectrometer equipped for an integrating sphere attachment using BaSO₄ as background. Brunauer Emmett-Teller (BET) specific surface area analysis determines the specific surface area (m²/g) of samples or, as a means of determining material by BET, the specific surface area for a sample measured to include the pore size distribution into the sample. The scanning electron microscope (SEM) uses a focused beam for high-energy electrons to produce a variety of signals on the surface of solid specimens to be analyzed. (Using EDS) It is capable of performing analyses of selected point locations in the samples; this tactic is especially useful in semi-quantitatively or qualitatively determining chemical composition elements that can be scanned at specific points. Transmission Electron Microscopy (TEM) is a technique from type a microscopy whereby a beam of electrons is transmitted through an ultrathin sample. An image is formed by the interaction of the electrons transmitted through the specimen.

Figure 1 shows the TGA of ZnTiAl-Pd-LDHs, MgTiAl-Pd-LDHs, and NiTiAl-Pd-LDHs to convert the catalysts from to ZnTiAl-Pd-LDOs, MgTiAl-Pd-LDOs and NiTiAl-Pd-LDOs that used as reference and heated from 25˚C to 700˚C with rate 5/min in air. There are the measurements and the gradient for samples were started at 20˚C temperature. All catalysts put in a crucible where the calcination process stabilized the samples disintegrated at 400˚C for 4 hours [10] . After calcination, the removal of water interlayer physically adsorbed on the external surface of the crystallites and removal of interlayer anions, with a weight loss rapidly of the catalyst. Where LDOs are destroyed and these obvious peaks disappear, reflection forms an amorphous material after calcination [14] [15] .

Figure 2 shows all crystal structures of the pristine ZnTiAl-LDHs, MgTiAl-LDHs, and NiTiAl-LDHs. Samples were examined by XRD for studying structure information and morphology of the Ti-containing LDHs (1) ZnTiAl-LDHs, (2) MgTiAl-LDHs, and (3) NiTiAl-LDHs. They were successfully prepared by using the co-precipitation method. Figure 2 shows XRD patterns diffraction patterns of (1) ZnTiAl-LDHs, (2) MgTiAl-LDHs, and (3) NiTiAl-LDHs. It can be seen from Figure 2 that the reflection diffraction peaks of two Theta degrees at (11.9˚, 23.6˚, 34.8˚, 46.8˚, 60.3˚, 61.7˚) correspond to the characteristic diffraction facets of (003), (006), (009), (015), (018), (110) and (113), respectively, of LDHs. It was found that the basic reflection (2 ≈ 11.9˚, d⁰⁰³ = 0.788 nm) for (1) ZnTiAl-LDHs. (2) MgTiAl-LDH shows similar reflections with a basal spacing (2 ≈ 11.9˚, d⁰⁰³ = 0.774 nm), which is indicative of different interlayer anions. In addition, it has been found that the basic reflection (2 ≈ 11.9˚, d⁰⁰³ = 0.722 nm) for (3) NiTiAl-LDHs. The Bragg reflections sharp is well defined for ZnTiAl-LDHs, which appear sharper and show more complete peaks. It has a much better crystallinity compared with NiTiAl-LDHs and MgTiAl-LDHs. The presence of one reflection peaks in the sample with the highest Ti⁴⁺Al³⁺contents, which can be due to the intercalation of NO₃ ions coexisting with intercalated ${\text{CO}}_3^{2-}$ ions. All catalysis diffraction peaks can be indexed by a rhombohedral structure with refined lattice parameters, which are steady with those of well-known LDH materials in ${\text{CO}}_3^{2-}$ sharp form. This variation in the cell parameter could be due to the different M^II/Ti⁴⁺Al³⁺ ratios in the materials since the increase in the positive charge could produce a higher repulsion between the material layers. LDHs can interchange the intercalated anions with different kinds of anionic molecules [16] [17] . The small incongruity is due to the estimation error of the water content and the residual carbonate ions in the reaction [18] . These values were similar to those reported in the literature [19] .

Samples were analyzed using the N₂-sorption isotherm, BET surface area, and Band Energy values for all the samples, which are shown in Figure 3 and Table 1 , where there are obvious differences in surface area for the three catalysts. The N₂ adsorption-desorption isotherm at 77 K and the corresponding pore size distribution curves for (A) ZnTiAl-Pd-LDO, (B) NiTiAl-Pd-LDO, and (C) MgTiAl-Pd-LDO are shown in Figure 3 . H3-type hysteresis loop (P/P0 > 0.4) suggests the presence of mesoporous for all catalysts. The better catalyst (A), ZnTiAl-Pd-LDO, shows the largest surface area (204.2645 m²/g) and band gap (2.86 eV), the highest availability activity for UV radiation among them as compared with other catalysts. Catalyst (B) NiTiAl-Pd-LDO surface area (175.5964 m²/g) and band gap (3.02 eV). Catalyst (C) MgTiAl-Pd-LDO surface area (116.3723 m²/g) and band gap (3.30 eV). This difference in the surface area of the catalyst is due to the change of the metal catalyst [9] .

Figure 4(A) for all catalysts for (M²⁺ = Zn, Mg, and Ni) M²⁺/Ti⁴⁺Al³⁺-CO³-LDO, LDO presented enhanced high absorption in the UV region (200 - 400 nm). The light absorption of the material and the transmigration of the light-induced electrons and holes are the keys to observing the photocatalytic reaction. The strong adsorption energy toward the molecules enhances the generation of photoinduced electro-hole pairs in active positions. Its comparison of the congruent absorption spectra between catalysts is clear. The results showed that UV-vis absorption of ZnTiAl-Pd-LDO followed the order of NiTiAl-d-LDO and MgTiAl-Pd-LDO. It can also inhibit the recombination and arrangement between photoelectrons and holes, but it is also an effective way to facilitate the rapid transfer of photoelectrons from bulk to the surface of catalysts.

Figure 4(B) shows the UV-vis absorption spectra reflectance in diffuse for (M²⁺ = Zn, Mg and Ni) M²⁺/Ti⁴⁺ Al³⁺-CO₃-LDO, where the band gap was calculated by using the formula (Eg) = 1240/λ (nm) consecrated. The wavelength was calculated using an approximate value conforming to the slope of the straightest line near the edge of the absorption onset. This is signifying proof of the directly allowed optical transition. We could view the band gap (Eg) of the catalysts. Table 1 shows the values of the difference between the band gaps in the catalysts. The results showed that the calculated band gap of ZnTiAl-Pd-LDO followed the order of ZnTiAl-Pd-LDO (2.86 eV) NiTiAl-d-LDO (3.02 eV) MgTiAl-Pd-LDO (3.30 eV) [9] [20] [21] .

Figure 5 shows the LDO of all samples that were analyzed by scanning electron microscope (SEM). The synthesized nanocomposite has been dispersed in ethanol for 10 min with mixed. Then, take a drop of the attached from a sample of the compound of the catalyst and place it on the carbon area in coated Cu. The SEM technique has been utilized to study the morphology of the nanoparticles, as can be seen in Figure 5 . Scanning electronic microscope (SEM) in images of (A) ZnTiAl-LDO, (B) NiTiAl-LDO, and (C) MgTiAl-LDO shows the main elements in the rhombohedral symmetry.

The synthesized Figure 5(A) and Figure 5(B) are composed of numerous nanoflakes and revealed very small irregular flakes and plate-like structures of different sizes. The Pd-LDH materials show particle sizes in the range of 100 nm. In addition, Figure 5(C) shows a nanosheet with interlocking hexagonal shapes that has a more pronounced topography [22] [23] .

Figure 6 and Table 2 show the confirmation of the chemical composition of the crystal product by SEM-EDS analysis. Where the main elements analysis results show the chemical composition of the crystals by the molar ratio of the elements that had been prepared in (A) NiTiAl-CO₃-Pd-LDO (B) ZnTiAl-CO₃-Pd-LDO and (C) MgTiAl-CO₃-Pd-LDO. This is to prove that the Pd was loaded on the surface of the catalyst LDHs. The EDS results roughly proved the composition of synthetic LDO, although the values cannot represent the accurate percent of each element from area [22] [23] .

Figure 7 shows the TEM images of the ZnTiAl-Pd-LDO nanocomposite. The synthesized nanocomposite was dispersed in ethanol for 10 minutes after mixing. Then, take a drop of the attached from a sample of the compound of the catalyst and place it on the carbon area in coated Cu. It is revealed that the thickness of the hexagonal plate-like structure is only about 50 nm. Figure 7 shows representative TEM images of LDO after photo-loading of Pd 1 wt% by UV irradiation times 120 min and after calcination at a temperature of 400˚C. It can be observed that LDO is the formation of a sheet-like structure with a particle size of 50 nm. This confirms the agglomeration of Pd particles on the surface of the LDO by transmission electron microscopy Figure 7 . Palladium nanoparticles appear as dark spherical spots in these samples. Pd nanoparticles are heterogeneously distributed on the LDO surface area, and particle sizes higher than 50 nm were observed [24] .

The photocatalytic reactions were performed in an inner irradiation system with a closed-equipped gas recirculation. A Pyrex cell with a flat window for illumination in all the experiments where photodeposition of palladium was loaded on the surface of layered double hydroxides (LDHs). Then, powder (1.0 wt%) of palladium chloride (II) (PdCl₂, Aldrich 99%) was added and dissolved in a solution of 10 ml deionized water. Then, 1 gram of LDHs was added to the mixture to obtain the palladium loading onto the surface of LDH. The photoreduction process was performed to highlight the comment period of 120 minutes with Xeon lamp light 400 W. It was dried in an oven at 40˚C for one night.

It is giving the product Pd/LDHs. Then, calcination of catalysis by air at a temperature of 400˚C for 4 h, then grounded, giving the product layered double oxide (Pd/LDO). About 0.080 mg of catalyst was used for the decomposition of the total liquid volume, which was around 40 mL of deionized water and (1.00 mg 0.0055 Mol) from glucose. The reaction system was evacuated by a mechanical pump and then filled with 1 MPa of high-purity N₂ (>99.99%). The hydrogen generation rate was obtained in a pure N₂ atmosphere. The hydrogen evolution initially increases with reaction time [21] . This process was repeated five times in order to remove O₂ from the system [22] . Powder photocatalysts were dispersed in the water by stirring with a magnetic stirrer. The temperature of the solution was controlled at about 40˚C by circulating water, and the reaction was conducted for 5 hours under 400 W Xe-lamp irradiation wavelength 365 nm. The 1.0 ml was taken from the bag gas sample. Periodically, during these experiments, a narrow gas syringe was injected into the analyzer SHIMADZU Gas Chromatograph (SGC). The detector was (DTCD1) type, and N₂ was used as a constant flow of carrier gas. The injector executor temperature was set at 90˚C, but the detector temperature column was set at 150˚C to detect the sample gas sample injected existing in the gas sample, which was replaced at the thermal conductivity of greenhouse gases to give quantitative and qualitative data for the gas sample.

Figure 8 shows the hydrogen production rate of different M²⁺/TiAl-Pd-LDO (M²⁺ = Mg, Ni, and Zn) catalysts. It is observed by changing the type of metals. The hydrogen production rate is changing. In addition, we were trying to determine the influence of activation energy on the difference in the hydrogen production rate for M²⁺/TiAl-Pd-LDO (M²⁺ = Mg, Ni and Zn). This result displays remarkable photocatalytic performance for glucose in hydrogen production. It is noted that ZnTiAl-Pd-LDO has the best performance in hydrogen production from glucose with (1.328 mmol∙g⁻¹∙h⁻¹) of the amount of hydrogen as compared with NiTiAl-Pd-LDO (0.182 mmol∙g⁻¹∙h⁻¹) and MgTiAl-Pd-LDO (0.127 mmol∙g⁻¹∙h⁻¹). Hydrogen production gradually increases with the change of the metals. This indicates a lack of regularity of Ni and Mg with glucose in hydrogen production. Moreover, catalysts containing Zn metal have higher photoactivity than other metals. Band gap energy, which is calculated from the UV spectrum, also supports this result. It is reported that highly dispersed active metals that help to increase photocatalysis effective sites enhance the efficiency of electron separation holes.