NANOPTEK CORPORATION

Patent Trials and Appeals Board

Sep 29, 2020

14680999 - (D) (P.T.A.B. Sep. 29, 2020)

UNITED STATES PATENT AND TRADEMARK OFFICE
UNITED STATES DEPARTMENT OF COMMERCE
United States Patent and Trademark Office
Address: COMMISSIONER FOR PATENTS
P.O. Box 1450
Alexandria, Virginia 22313-1450
www.uspto.gov
APPLICATION NO. FILING DATE FIRST NAMED INVENTOR ATTORNEY DOCKET NO. CONFIRMATION NO.
14/680,999 04/07/2015 John Michael Guerra G-CIP4CON 5831
26125 7590 09/29/2020
DAVID J. COLE
7 LAKESHORE DRIVE
MEDWAY, MA 02053-1034
EXAMINER
WILKINS III, HARRY D
ART UNIT PAPER NUMBER
1796
NOTIFICATION DATE DELIVERY MODE
09/29/2020 ELECTRONIC
Please find below and/or attached an Office communication concerning this application or proceeding.
The time period for reply, if any, is set in the attached communication.
Notice of the Office communication was sent electronically on above-indicated "Notification Date" to the
following e-mail address(es):
DAVIDJOHNCOLE@GMAIL.COM
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
BEFORE THE PATENT TRIAL AND APPEAL BOARD
Ex parte JOHN MICHAEL GUERRA
Appeal 2020-000098
Application 14/680,999
Technology Center 1700
Before TERRY J. OWENS, CATHERINE Q. TIMM, and
JEFFREY B. ROBERTSON, Administrative Patent Judges.
ROBERTSON, Administrative Patent Judge.
DECISION ON APPEAL1

1 This Decision includes citations to the following documents: Specification
filed April 4, 2015 and as amended on February 22, 2017 (“Spec.”); Final
Office Action mailed June 5, 2018 (“Final Act.”); Appeal Brief filed
November 5, 2018 (“Appeal Br.”); Examiner’s Answer mailed February 1,
2019 (“Ans.”); and Reply Brief filed April 30, 2019 (“Reply Br.”).
Appeal 2020-000098
Application 14/680,999

2
STATEMENT OF THE CASE
Pursuant to 35 U.S.C. § 134(a), Appellant2 appeals from the
Examiner’s decision to reject claims 1–8, 10–14, and 17–26.3
Appeal Br. 15. We have jurisdiction under 35 U.S.C. § 6(b).
We affirm in part.
CLAIMED SUBJECT MATTER
Appellant states the invention relates to a bandgap-shifted
semiconductor surface, and a method for making the same. Spec. ¶ 5.
Claims 1 and 7, reproduced below, are illustrative of the claimed subject
matter (Appeal Br., Claims Appendix 31–33):
1. A photoelectrolytic cell for production of first and second
gases from a liquid, the cell comprising:
a container capable of holding the liquid;
a photoelectrode disposed within the container and capable of
generating the first gas upon exposure to radiation, said
photoelectrode having been produced by a process comprising:
(a) etching titanium metal to form a titanium nano-structured
surface on said titanium metal; and
(b) oxidizing at least part of the nano-structured titanium to
titania by at least one of (i) anodizing the titanium in an anodizing
solution, and (ii) heating the titanium in an oxygen-containing
atmosphere, wherein the titania film produced in step (b) is
stressed by the nanostructures produced in step (a), the stress
causing the titania film to have a bandgap therein to support
spontaneous photoelectrolysis of water in visible light;

2 We use the word “Appellant” to refer to “applicant” as defined in 37
C.F.R. § 1.42. Appellant identifies Nanoptek Corporation as the real party
in interest. Appeal Br. 3.
3 Claims 9, 15, and 16 have been cancelled. See Appeal Br. 5.
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a counterelectrode disposed within the container electrically
connected to the photoelectrode and capable of generating a
second gas when the photoelectrode is exposed to radiation; and
a membrane arranged between the photoelectrode and the
counterelectrode to separate the first and second gases.

7. A photoelectrolytic cell for production of at least one gas
from a liquid, the cell comprising:
a container capable of holding the liquid;
a photoanode disposed within the container;
a cathode disposed within the container and electrically
connected to the photoanode, such that when the photoanode is
exposed to radiation, at least one gas will be generated by the
photoanode and the cathode; and
a second anode disposed within the container, the second
anode not being photolytically active but being electrically
connected to the cathode,
said photoanode comprising a semiconductor film on a
substrate, the semiconductor film having a bandgap not
supporting spontaneous photoelectrolysis of water in visible light
wavelengths present in sunlight, the substrate having surface
undulations with a spatial period smaller than the wavelength of
visible light that cause stress in the semiconductor film and
thereby shift the bandgap therein to support spontaneous
photoelectrolysis of water in visible light.

Independent claims 10 and 23 also stand rejected, and are directed to
an apparatus and a photo-reactor core assembly means, respectively. Id. at
33–36.
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Application 14/680,999

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REFERENCES
The prior art relied upon by the Examiner is:
Name Reference Date
Kilby et al.
hereinafter “Kilby”
US 4,021,323 May 3, 1977
Powell US 4,278,829 July 14, 1981
Murphy US 4,722,776 Feb. 02, 1988
Pritchard US 5,592,028 Jan. 07, 1997
Scannell et al.
hereinafter
“Scannell”
US 5,660,698 Aug.26, 1997
Converse US 6,015,950 Jan. 18, 2000
Guerra US 2003/0228727 A1 Dec. 11, 2003
Shifman US 2005/0046977 A1 Mar. 3, 2005
A. G. Imenes et al.
hereinafter “Imenes”
“Spectral beam splitting
technology for increased
conversion efficiency in
solar concentrating
systems: a review”
Solar Energy Materials
& Solar Cells 84 (2004)
19–69.
June 1, 2004
X. Quan et al.
hereinafter “Quan”
“Preparation of Titania
Nanotubes and Their
Environmental
Applications as
Electrode” Environ. Sci.
Technol. 2005, 39,
3770–3775.
2005
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R. Markle “Etching Titanium with
HF and Nitric Acid
Solutions Part 1”
Chemcut Corporation
2015
REJECTIONS
1. The Examiner rejected claims 1, 5, 6, and 21 under 35 U.S.C.
§ 103(a) (pre-AIA) as unpatentable over Guerra, Quan, with
evidence from Markle. Final Act. 3–5.
2. The Examiner rejected claim 2 under 35 U.S.C. § 103(a) (pre-AIA)
as unpatentable over Guerra, Quan, and Scannell. Final Act. 5–6.
3. The Examiner rejected claims 3 and 4 under 35 U.S.C. § 103(a)
(pre-AIA) as unpatentable over Guerra, Quan, and Murphy. Final
Act. 6–7.
4. The Examiner rejected claim 22 under 35 U.S.C. § 103(a) (pre-
AIA) as unpatentable over Guerra, Quan, and Kilby. Final Act. 7.
5. The Examiner rejected claim 25 under 35 U.S.C. § 103(a) (pre-
AIA) as unpatentable over Guerra, Quan, and Pritchard. Final Act.
7–8.
6. The Examiner rejected claim 7 under 35 U.S.C. § 103(a) (pre-AIA)
as unpatentable over Guerra and Murphy. Final Act. 8–9.
7. The Examiner rejected claim 8 under 35 U.S.C. § 103(a) (pre-AIA)
as unpatentable over Guerra, Murphy, and Scannell. Final Act. 9.
8. The Examiner rejected claims 10, 17, and 20 under 35 U.S.C.
§ 103(a) (pre-AIA) as unpatentable over Imenes, Guerra,
Converse, and Quan, with evidence from Markle. Final Act. 9–12.
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9. The Examiner rejected claims 11 and 12 under 35 U.S.C. § 103(a)
(pre-AIA) as unpatentable over Imenes, Guerra, Converse, Quan,
and Shifman. Final Act. 12.
10. The Examiner rejected claim 13 under 35 U.S.C. § 103(a) (pre-
AIA) as unpatentable over Imenes, Guerra, Converse, Quan, and
Powell. Final Act. 12–13.
11. The Examiner rejected claim 14 under 35 U.S.C. § 103(a) (pre-
AIA) as unpatentable over Imenes, Guerra, Converse, Quan, and
Kilby. Final Act. 13–14.
12. The Examiner rejected claims 18 and 19 under 35 U.S.C. § 103(a)
(pre-AIA) as unpatentable over Imenes, Guerra, Converse, Quan,
and Murphy. Final Act. 14–15.
13. The Examiner rejected claim 26 under 35 U.S.C. § 103(a) (pre-
AIA) as unpatentable over Imenes, Guerra, Converse, Quan, and
Pritchard. Final Act. 15.
14. The Examiner rejected claim 23 under 35 U.S.C. § 103(a) (pre-
AIA) as unpatentable over Guerra, Quan, and Scannell, with
evidence from Markle. Final Act. 15–17.
15. The Examiner rejected claim 24 under 35 U.S.C. § 103(a) (pre-
AIA) as unpatentable over Guerra, Quan, Scannell, Imenes,
Converse, and Shifman. Final Act. 17–19.

OPINION
Rejection 1
We limit our discussion to claim 1, which is sufficient to dispose of
this rejection.
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The Examiner’s Rejection
In rejecting claim 1 as unpatentable over Guerra and Quan, the
Examiner found Guerra discloses a photoelectrolytic cell having the
structure recited in claim 1, but Guerra discloses a photoelectrode made by
vacuum deposition of titania, rather than forming a titania photoelectrode by
the etching and oxidizing steps on titanium recited in claim 1. Final Act. 4.
The Examiner found Quan discloses a method of preparing titania nanotube
electrodes where a titanium sheet is immersed in a chemical etchant, and
then anodized to produce a titania film with a structure of nanotubes. Id.
The Examiner determined it would have been obvious to have substituted
the titania film of Quan for the titania film of Guerra, because Quan
discloses the titania film disclosed therein increases the photoconversion
ability of titania. Id. at 5.

Appellant’s contentions
Appellant does not dispute that Guerra discloses the basic apparatus
recited in claim 1. Appeal Br. 18. Rather, Appellant contends, inter alia,
that Quan does not disclose titania electrodes that have excellent
photoelectrolytic properties for splitting water in visible light. Id. at 19–20.
In particular, Appellant contends that the bandgap for the titania electrodes
disclosed in Quan is larger than is required for efficient photoelectrolysis of
water using sunlight. Id. at 20–22. Thus, Appellant contends that one of
ordinary skill in the art would not have considered modifying Guerra to
include the Quan electrode. Id. at 21.

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Issue
Did the Examiner err in determining it would have been obvious to
have substituted the titania nanotube film of Quan for the vaccum-deposited
titania film in Guerra to produce a photoelectrolytic cell that “support[s]
spontaneous photoelectrolysis of water in visible light” as recited in claim 1?

Discussion
We are persuaded by Appellant’s arguments. Guerra discloses a
titania photocatalyst with a band gap that is shifted and broadened to be
active for photoelectrolysis at wavelengths more prevalent in sunlight and
artificial light. Guerra ¶ 17.
With respect to the shifting the band gap, Guerra discloses that the
energy band gap of conventional titania electrodes is 3.0 eV, and requires
artificial light such as a xenon lamp. Guerra ¶ 8. However, Quan discloses
that the band gap of the titania nanotubes is 3.30 eV. Quan 3772, 1st
column. Thus, Quan discloses a shift in the band gap of titania toward
shorter wavelengths, i.e., away from wavelengths more prevalent in sunlight
and deeper into UV wavelengths, which is the opposite of the band gap shift
disclosed in Guerra. Indeed, Quan discloses evaluation of its titania
nanotubes using UV irradiation via a high-pressure mercury lamp. Id. at
3771, 1st column.
In addition, although the Examiner points to Figure 5 of Quan for the
position that the band gap of the titania nanotube is broadened because of the
absorption (~0.1 Abs) shown in wavelengths from 400–500 nm (Ans. 21–
22; Quan, p. 3772, Fig. 5, curve b), we agree with Appellant (Reply Br. 6)
that Quan discloses band gap absorption range edge is 350 nm, such that one
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of ordinary skill in the art would not have assigned any particular
significance to the absorption in Figure 5 relied upon by the Examiner.
Moreover, the Examiner’s position that one of ordinary skill in the art would
have been able to adjust the band gap that is capable of spontaneous
photoelectrolysis of water in visible light in view of Guerra (Ans. 22, citing
Guerra, ¶ 109) appears to be contrary to Quan’s disclosure of shifting the
bandgap toward shorter wavelengths. See Quan p. 3773, 1st column.
Although Quan discloses a titania electrode with a nanotube structure
that is the “kind of electrode may find its important roles . . . in splitting of
water to produce hydrogen and oxygen and selective organic synthesis”
(Quan, p. 3770, 2nd column), and “photoconversion ability of titania by
modification was greatly improved” (id. at 3774, 2nd column), in view of the
above discussion, we do not view these disclosures to be sufficient to
support the Examiner’s rationale that it would have been obvious to have
used Quan’s titania nanotube film in Guerra’s photoelectrolytic cell to have
a band gap that “support[s] spontaneous photoelectrolysis of water in visible
light” as recited in claim 1.
Accordingly, we reverse the Examiner’s rejection of claim 1, and
claims 5, 6, and 21 dependent therefrom.

Rejections 2–5 and 8–15
The Examiner’s rejections of the claims including independent claims
10 and 23 suffer from the same deficiencies as discussed above with respect
to claim 1 and Rejection 1, where each of those rejections rely on Guerra
and Quan, and the added prior art references fail to remedy the deficiencies
identified above. See Final Act. 5–19. In this regard, we observe that claim
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23 expressly recites “the stress causing the titania film to have a lower
bandgap than unstressed titania” such that Quan’s disclosure of an higher
bandgap as discussed above is sufficient to demonstrate reversible error on
the part of the Examiner.
Accordingly, we reverse the Examiner’s rejections for similar reasons
as discussed above with respect to claim 1.

Rejection 6
The Examiner’s Rejection
In rejecting claim 7 over Guerra and Murphy, the Examiner found
Guerra discloses a photoelectrolytic cell as recited in claim 7 including
undulations in the titania surface with a spatial period smaller than the
wavelength of visible light, which enhanced the ability of titania to conduct
photolysis. Final Act. 8. The Examiner found, however, that Guerra fails to
disclose a second anode disposed within the container, where the second
anode is not photolytically active, but is electrically connected to the
cathode. Id. The Examiner found Murphy discloses photoelectrolytic
production of hydrogen was known, as was utilizing an external photovoltaic
cell to energize an anode and a cathode located within a container. Id. The
Examiner determined it would have been obvious to have added a second
anode to the system of Guerra into a single container to permit application of
additional electricity from an external source to produce more hydrogen and
achieve higher rates of hydrogen production through the combination of the
photoelectrolytic anode of Guerra and a non-photocatalytic anode. Id. at 8–
9.

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Appellant’s contentions
Appellant contends Murphy does not support the idea of using a
second non-photolytically active anode in the container as required in claim
7. Appeal Br. 25. Appellant argues Murphy discloses using an external
electrical source increases costs, reduces efficiency, and increases space
requirements, such that Murphy discloses elimination of an external
electrical energy source. Id. at 26. Appellant argues Murphy discloses a
device that keeps the light-activated semiconductor surface out of aqueous
solution in order to overcome these problems, which teaches away from the
modification of the Guerra apparatus as set forth in the Examiner’s rejection.
Id. at 27. Appellant argues Murphy discloses a compound electrode, where
one side is a light-driven semiconductor device and the other side comprises
an electrocatalyst, and where the two sides are connected via an ohmic layer.
Id. Appellant contends Murphy does not disclose a non-photolytic electrode
immersed in electrolyte or the use of external electrical power in his
apparatus, such that even if combined, it would be impossible to electrically
connect an external electrical power source between the photoelectrode of
Murphy and the Guerra cathode as required by claim 7. Id. at 28.

Discussion
We are not persuaded by Appellant’s arguments. As the Examiner
points out, Murphy discloses multiple ways to conduct splitting of water in
order to generate hydrogen gas. Ans. 25, citing Murphy, col. 1, ll. 25–32.
The Examiner’s rejection relies on combining a photoelectrolysis system as
disclosed in Guerra with an electrolysis system of the prior art, where there
is an external source of electric potential in a single container to provide a
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system that is capable of functioning independently with light or with
externally supplied electricity, or both simultaneously. Id. In this way, the
Examiner found the combined apparatus would have the advantage of being
able to operate during the day by solar energy and the available electricity
source during the night or during periods of clouds. Id. Thus, the Examiner
does not rely on the particular semiconductor electrodes or devices disclosed
in Murphy.
In this regard, Appellant acknowledges that Murphy discloses an
electrolyzer where the cathode and anode are in the container (Reply Br. 9),
which is consistent with the Examiner’s rationale. In addition, Appellant’s
argument that Murphy does not teach the addition of a photoelectrode within
the container (Reply Br. 9–10) does not consider the Examiner’s rejection as
a whole, which relies on Guerra for the photoactive anode. Appellant’s
further argument that Guerra does not disclose a photoactive anode that
comprises titania on a titanium substrate (Reply Br. 10) is also not
persuasive, as it is not commensurate in scope with claim 7, which does not
recite this feature.
Accordingly, we affirm the Examiner’s rejection of claim 7.

Rejection 7
Appellant does not set forth separate arguments with respect to claim
8, which depends from claim 7, but rather relies on the dependency of claim
8 for its patentability. Appeal Br. 29.
Accordingly, we affirm the Examiner’s rejection of claim 8 for similar
reasons as discussed above with respect to claim 7.
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DECISION SUMMARY
In summary:
Claims
Rejected
35 U.S.C.
§
Reference(s)/Basis Affirmed Reversed
1, 5, 6, 21 103(a) Guerra, Quan,
Markle
1, 5, 6, 21
2 103(a) Guerra, Quan,
Scannell
2
3, 4 103(a) Guerra, Quan,
Murphy
3, 4
22 103(a) Guerra, Quan,
Kilby
22
25 103(a) Guerra, Quan,
Pritchard
25
7 103(a) Guerra, Murphy 7
8 103(a) Guerra, Murphy,
Scannell
8
10, 17, 20 103(a) Imenes, Guerra,
Converse, Quan,
Markle
10, 17, 20
11, 12 103(a) Imenes, Guerra,
Converse, Quan,
Shifman
11, 12
13 103(a) Imenes, Guerra,
Converse, Quan,
Powell
13
14 103(a) Imenes, Guerra,
Converse, Quan,
Kilby
14
18, 19 103(a) Imenes, Guerra,
Converse, Quan,
Murphy
18, 19
26 103(a) Imenes, Guerra,
Converse, Quan,
Pritchard
26
23 103(a) Guerra, Quan,
Scannell, Markle
23
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24 103(a) Guerra, Quan,
Scannell, Imenes,
Converse, Shifman
24
Overall
Outcome
7, 8 1–6, 10–14,
17–26
TIME PERIOD FOR RESPONSE
No time period for taking any subsequent action in connection with
this appeal may be extended under 37 C.F.R. § 1.136(a). See 37 C.F.R.
§ 1.136(a)(1)(iv).

AFFFIRMED IN PART